When the body's thermoregulation normalizes in newborns. Features of thermoregulation in a child, mechanisms of heat production and heat generation, requirements for clothing and ambient temperature, depending on the period of development of the child
The newborn was born from the uterus, where the temperature was fairly constant and was 38-38.5’C. On earth one cannot dream of such a temperature or its constancy. Therefore, the process of a child’s adaptation to new temperature conditions should be gentle and gradual.
Thermal adaptation is the process of adaptation of a newborn and infant to a new temperature regime in conditions of extrauterine existence. Thermal adaptation of a newborn occurs during daily air baths, while washing and bathing, subject to full holding and breastfeeding.
Initially, the mother provides thermal adaptation to the baby. On the one hand, it should prolong the conditions of intrauterine comfort for the child, and on the other, give him the opportunity to meet the new world, get to know it and safely adapt to new influences. To ensure intrauterine comfort, the mother carries the baby on herself and breastfeeds him, which prolongs contact with the usual maternal warmth.
Periodically, she puts the child aside to treat or change him, at which time he takes short-term air baths. She also regularly, 4-5 times a day, washes the child.
In order for thermal adaptation to be complete, the child should be washed with water of different temperatures. To do this, the mother, without choosing, washes him with either cold or warm water. After a while, the child begins to react completely calmly to water of any temperature and simply waits patiently until they finish washing him.
Hypothermia and overheating
A newborn cannot independently maintain his body temperature, so he is extremely sensitive to overheating and hypothermia. The mother must warm the baby with her warmth so that cooling does not occur, and save him from the heat so that there is no overheating.
The baby's tummy is most sensitive to cooling. Insufficient warming of the baby's abdomen disrupts the functioning of his intestines, which threatens bloating. In addition, cooling adversely affects the functioning of the kidneys and adrenal glands. To determine whether the child is cold, the mother must first focus on the subjective perception of external temperature. To do this, she should be dressed a little lighter than the baby, because a newborn will always be colder than an adult.
For example, if the mother is wearing a T-shirt and shorts, then the child should be dressed in a T-shirt or a cotton vest, and if the mother is wearing a sweater, then the child should be wearing a vest, a warm blouse and a flannel diaper.
Overheating is no less dangerous for a child’s body and can lead to heat stroke. Therefore, if the baby is hot, he should be removed from his excess clothes, washed with cool water to make him more comfortable, and outside he can be hidden in the shade.
The mother should monitor the ambient temperature and, if possible, regulate it to avoid adverse effects on the child.
How to understand that a child is cold?
If the baby is not cold, then his skin should be an even pink color, it should not become bluish or marbled. However, cyanosis of the baby’s feet and hands is not a sign of cooling.
The skin should feel warm or cool to the touch, but not cold.
The armpits should be warm, as well as the folds under the knees, elbows, and groin. The coldness in these folds indicates that the child is cooling.
If the child has been lying separately from the mother for 20 minutes, in order to avoid cooling, he should be picked up in order to warm him with the mother's warmth.
Hardening
Successful thermal adaptation is the basis for further hardening of the child. Hardening is the formation of the body’s resistance to environmental influences. The influence of temperature is only one of the influences of the external environment.
The need for hardening should be determined by lifestyle. If a person walks in the snow because he needs to run out every day to get firewood, these are the most optimal conditions for hardening.
All artificial measures do not give sustainable results and can even undermine health. For successful hardening, the child’s conscious desire to test his endurance is important, so hardening procedures should begin no earlier than 5-6 years. It is at this age that children are ready to test their body's endurance.
http://www.mirwomne.ru/deti-do-goda/articles/fiziologiya-malischa/termoregulyaziya-u-grudnichka/
Thermoregulation is a set of physiological processes that ensure the maintenance of optimal body temperature.
In a newborn baby, thermoregulation is not perfect. At birth, the body is close to the mother’s body temperature and is equal to 37.7-38.2 ° C. Within a few hours after birth, it decreases by 1.5-2.0 °C, and then rises again to 37 °C.
In immature, premature babies, the temperature drops below Normal during the first days of life. A decrease in body temperature in a full-term baby is called transient hypothermia of the newborn.
Approximately 0.3-0.5% of newborns experience hyperthermia on the 3rd-5th day of life. This phenomenon is explained by the colonization of bacterial flora and dehydration of the child’s body. After the 5th day, body temperature remains very sensitive to fluctuations in ambient temperature. Body temperature changes slightly when children are fed or swaddled. Establishment of normal temperature occurs only by 1.5-2 months of life, and in premature infants at a later date.
After establishing a normal daily rhythm, the temperature in the armpits and groin is approximately 36.1-36.6 °C, in the rectum - 37.1-37.5 °C.
After the neonatal period, an increase in body temperature in a child is most often associated with infection. In children up to about 9-10 months of age, the temperature may rise when dehydrated.
The central link of thermoregulation is the hypothalamic region. Therefore, various effects on the hypothalamus can also cause an increase in temperature (hypoxia of the fetus and newborn, intracranial injury of the newborn, abnormalities of brain development).
The so-called non-contractile thermogenesis influences the body temperature of a child in the first months of life. Heat formation in young children occurs due to fat.
A more advanced type of heat production is contractile thermogenesis. It is created by increasing muscle activity. Therefore, it increases significantly when a child is exposed to cold. The mechanisms of heat production in children are disrupted during labor hypoxia, against the background of respiratory diseases, and the administration of certain medications (β-blockers).
Heat transfer processes mature only by 7-8 years. Heat transfer is also regulated by sweating, which is still imperfect in children of the first years of life. Therefore, for children under the age of 7-8 years, it is necessary to organize optimal temperature conditions. The child can be undressed and not lose heat if he is in the thermoneutral zone. For newborn full-term babies it is 32-35°C, for premature babies - 35-36°C, for a swaddled full-term baby - 23-26°C, and for a premature baby - 30-33°C. By the age of 1 month, the limits of the thermal zone shift downwards by 1.5-2.0°C for swaddled children. To create conditions for thermoregulation, the baby’s head is not covered when swaddling. When nursing premature babies until thermoregulation is improved, they are kept in incubators.
Failure to comply with the optimal temperature regime in young children leads to impaired brain development, diseases of the respiratory system and cardiovascular system. Therefore, immediately after birth, children are swaddled in warm diapers. Examination, change of linen, treatment of the skin and navel are carried out quickly on a heated changing table. For a premature baby, all manipulations are carried out in an incubator.
Overheating a child is no less dangerous than hypothermia. Firstly, in children, even with temporary overheating, dehydration of the body develops; secondly, impaired microcirculation due to overheating leads to heat stroke or shock, dysfunction of the central nervous system, heart, etc.
The same situation is possible when hyperthermia is caused by infectious diseases. A child can die from overheating, so if he has hyperthermia, he needs emergency help.
Comfortable temperature conditions are created for infants. In the room where they are located, air humidity is 30-60%, air speed is 0.12-0.2 m/s, air temperature is 21-22 °C. From two years of age, the comfort temperature drops to 18 °C, and for a relative optimum thermal state - even to 16 °C.
It is important to dress your child correctly and adequately. In winter, outdoors, the child should wear 4-5 layers of clothing, including a windproof top layer. In winter, overalls or bib overalls are usually used for walking. In summer, depending on the air temperature, there can be up to two layers of clothing at an air temperature of 23°C and above, and up to three at an air temperature of 16-17°C.
To prevent cooling and overheating, methods of hardening children are widely used. Hardening should be gradual, short-term - using cold (pulse) contact with the child’s skin, with a gradual spread of the cold irritant over the skin area and changing the timing of hardening. First, it is pouring over the feet with a decrease in temperature. Then a one-time douse with cold water from the legs to the thigh, from the navel to the neck and head. With systematic and repeatable douches, adaptation devices mature, which entails an increase in the time of these procedures.
To develop cold resistance and adaptive reactions, two douches per week are enough for children. It is better to carry them out in the spring. Large doses of hardening procedures cause disruption of adaptive reactions, lead to hyperstimulation of the adrenal glands and cause immunodeficiency states.
Hardening procedures in children should not cause a decrease in core body temperature. It is also necessary to remember about the individual hardening regime, since each child reacts to cold stimuli in its own way.
In children's medical institutions, they also use such forms of hardening as sleeping in the open air, cold air baths, wiping with wet cold sheets, general dousing, foot baths and dousing the feet with a gradual decrease in temperature from 36.6 to 32.6 ° C. In some children's clinics, for hardening children, they use swimming pools with procedures for briefly dousing children with a stream of cold water, etc.
There are children whose temperature rises to 37.3-37.5°C for no apparent reason, although they are healthy. Most often this is a response to a temperature reaction to food intake, increased physical activity or increased psycho-emotional tone.
A temperature above 37.5°C, which is caused by some disease, is considered pathological. In this case, the state of heat production always prevails over heat transfer. Chills are often associated with contractile thermogenesis. Such conditions are caused by substances called pyrogens, which act on the thermoregulatory centers of the central nervous system.
There are different types of pathological temperature reactions.
The frequency of temperature registration in children is determined by the doctor - 2 times a day, after 1 hour, after 2 hours, etc. Registration of temperature during the day is carried out by nursing staff.
Body temperature below 36.4 °C is most often observed in children with reduced energy metabolism due to severe disease of the internal organs. This is exhaustion (dystrophy), vascular insufficiency, insufficiency of the functions of the main organs and systems. During shock, especially anaphylactic shock, the temperature also drops below normal.
Mechanisms of pathogenesis of thermoregulation disorders in newborns and children of the first year of life. Features of thermoregulation in children.
Yulish E.I.,
Donetsk State Medical University. M. Gorky
Summary: The work presents the mechanisms of pathogenesis of thermoregulation disorders in newborns and children of the first year of life.
Key words: thermoregulation, young children
A doctor should always prescribe some kind of medicine - today this stereotype is quite clearly formed among the population. And practical doctors successfully support it, reducing all relationships with the patient to a generous prescription of various medications. This approach leads to the fact that the population, including children, consumes a huge amount of medications. All this, along with the aggressiveness of advertising, information “permissiveness” and the availability of the drugs themselves, makes a significant, if not decisive, contribution to the irrational treatment of diseases. The consequences of such therapy are not only significant financial and economic losses (up to 30–50%), but also an obvious negative impact on the health of the population, the deterioration of which is often declared in various circles of society. At the same time, it must be recognized that targeted studies of this issue are rare, and the problem as a whole remains outside the close attention of both health care organizers and medical scientists.
An increase in body temperature is the most common cause and symptom of diseases for which parents and children consult a pediatrician. The causes and magnitude of the rise in body temperature in children, the dynamics and mechanisms of development of temperature reactions are extremely diverse, which requires the development of various tactics for its correction. Most practitioners perceive an increase in temperature in a child as a symptom that requires immediate elimination, especially when it comes to young children, although only clarification of the cause of the increase in temperature creates an objective basis for determining adequate and effective methods for correcting this symptom and treating the disease itself. Thus, according to survey data, in 40% of cases doctors prescribe antipyretics, although the child’s temperature does not exceed 37.8 °C. The most popular antipyretics are paracetamol, ibuprofen, nimesulide, viburkol (suppositories), and 5% - metamizole sodium (!). At the same time, an increase in temperature is a necessary reaction of the body, contributing to the formation of a complex process of its protection during a viral infection, and the aggressive and irrational use of antipyretics, certainly affecting the clinical manifestations of the disease, can significantly complicate the diagnosis and choice of timely therapy, which is especially important for children early age.
Before making a decision on tactics in relation to elevated temperature, you should try to answer a number of questions to determine the feasibility, necessity and method of therapeutic interventions, their safety and the possible consequences of using certain treatment methods: what value of the child’s body temperature is considered normal and how assess the degree of its increase; what is the cause and mechanism of increased body temperature in a child; is an increase in body temperature, hyperthermia or a manifestation of fever.
One of the most important conditions for the correct answer to these questions is knowledge of the characteristics of thermoregulation in children. It is known that in a growing organism metabolic processes occur with high intensity and constantly. At the same time, various forms of metabolic energy received and expended are converted into heat. A significant contribution to the formation of heat in a child's body (heat production - TP) is made by the high levels of metabolism and physical activity characteristic of children. The accumulation of heat in the body contributes to an increase in body temperature. However, in accordance with the physical laws of heat transfer, if the temperature of any body, including the human body, becomes higher than the temperature of the environment of its existence, heat from the surface of the body begins to dissipate into this environment (heat transfer - TO), which helps to lower the body temperature. It is obvious that the temperature for a given body will be constant if the values of TP and TO are equal. It is the maintenance of equality of heat production and heat transfer in conditions of changes in the intensity of metabolism, physical activity of the body and/or the temperature of the living environment that is one of the most important functions of the thermoregulation system.
The value of body temperature, upon achieving equality between the values of TP and TO, could be set at various arbitrary levels, but thanks to the function of the central hypothalamic thermoregulation centers, this temperature value is quite definite - 37 ° C and is called the thermoregulation set point. Thus, the formation by the central neural structures of the hypothalamus of a certain temperature regulated in a given organism is the most important function of the thermoregulation system. If this function is performed successfully, then the thermoregulation system provides a solution to its main task - maintaining the temperature of the brain and other tissues of the “core” of the body at a relatively constant level. This temperature is maintained at a minimum voltage of the thermoregulation mechanisms under conditions of slight fluctuations in the temperature of the external air environment or within the so-called thermoneutral, or thermoindifferent, zone: for a naked adult - in the range of 28–30 ° C, for a newborn - 32–34 ° C, for lightly dressed children aged 1 month. - 22–25 °C, 6 months. - 19–23 °C, 1 year - 17–20 °C.
The total heat production in the body consists of primary heat released during metabolic reactions that constantly occur in all organs and tissues, and secondary heat generated when the energy of high-energy compounds is spent to perform muscle work and other functions. A child’s TP depends on the value of the basal metabolic rate, the “specific dynamic action” of food taken, muscle activity and changes in metabolic rate associated with changes in environmental temperature (facultative thermogenesis). Metabolic processes are carried out with unequal intensity in different organs and tissues, and therefore the contribution to the overall TP of the body of individual organs and tissues is unequal. The greatest amount of heat is generated in the liver, kidneys, brain, working muscles (with tonic tension and contraction - contractile thermogenesis).
The amount of heat necessary to maintain body temperature is produced in a full-term baby immediately after birth. TC in a newborn is about 1.5 kcal per 1 kg of body weight per 1 hour. An increase in heat production after birth is ensured by the activation of the oxidation of free fatty acids in the mitochondria of fat cells, the level of which increases with an increase in the tone of the sympathetic nervous system, stimulation of adrenergic receptors by catecholamines and activation of protein kinase A , which increases the activity of the brown adipose tissue lipase enzyme. A more powerful and long-lasting increase in heat production is achieved by the action of thyroid hormones on mitochondrial oxidation processes in fat cells. In this case, the enhancement of TP is achieved by accelerating basic metabolic processes (basal metabolism) and activating the mechanisms of facultative thermogenesis, which ensure increased heat generation under conditions of lowering the ambient temperature. Both the intensity of basal metabolism in the body and the thermogenic function of brown adipose tissue depend on the level of thyroid hormones. Oxidation of fatty acids in brown adipose tissue, the mass of which in a full-term newborn is about 2% of body weight (25–35 g), occurs without significant synthesis of macroergs and with the maximum possible formation of primary heat. White adipose tissue of a newborn is also capable of direct heat generation, but to a much lesser extent. Using the mechanism of non-contractile thermogenesis, the level of heat production can be increased several times compared to the level of basal metabolism. At the same time, even in full-term babies, the reserves of heat-forming adipose tissue, including brown, quickly decrease, reaching a minimum by the 3-4th week after birth. The higher the serum level of T4 and T3, the higher the level of gene expression in the nuclei of adipocytes of brown adipose tissue, which are responsible for the synthesis of the thermogenin protein, which uncouples the processes of respiration and phosphorylation, reduces ATP synthesis in mitochondria and increases heat generation. T3 influences thermogenesis in brown adipose tissue by modulating the activity of the enzyme deiodinase D2, which determines the rate of formation of other active forms of thyroid hormones from T4 and their metabolic breakdown in tissues. Maximum stimulation of thermogenin gene expression is achieved by the simultaneous action of thyroid hormones and catecholamines. By the time of birth, this action reaches its greatest severity and provides the conditions for maximum thermogenic activity of brown adipose tissue in the early postnatal period.
With a significant degree of prematurity, when newborns have varying degrees of hypothyroidism, and the mass of brown adipose tissue is less than 1% of body weight, heat production is reduced. This can contribute to the development of hypothermia if conditions are not created to limit heat loss.
Contractile thermogenesis is also an important mechanism for increasing TP in a newborn, who already from the first hours of life has an increase in muscle tone and motor activity, which sharply increases with cold exposure to the skin. The role of contractile thermogenesis in increasing heat production increases as the child’s age increases and the mass of brown adipose tissue decreases. This is facilitated by an increase in muscle mass in children, the development of mechanisms of thermoregulatory muscle tone and cold shivering. The contribution of contractile thermogenesis to TP can change in a number of neurological and muscular diseases, as well as in the development of hypoxia caused by diseases of the circulatory and respiratory organs.
Heat production per 1 kg of body weight increases during the first year of life to 2.4 kcal per 1 hour. In children over 2 years of age, heat production per unit of body weight at rest gradually decreases, but at the same time the relative body surface area decreases, and by 15–17 years, heat exchange rates and the development of thermoregulation mechanisms approach those characteristic of adults, when TP and TO become balanced and amount to about 1 kcal per 1 hour.
As mentioned earlier, heat transfer plays a huge role in heat transfer. The following mechanisms of heat transfer by the body to the environment are distinguished: radiation, heat conduction, convection, moisture evaporation. TO in the first three ways can only be carried out if the body surface temperature is higher than the temperature of the environment of existence. Maintenance due to the evaporation of moisture can be carried out both in the presence of a positive temperature difference between the surface of the body and the environment, and in conditions of a higher ambient temperature. Maintenance by evaporation stops when the external air environment is 100% saturated with water vapor or in water.
Due to the occurrence of physiological reactions of the body to the effects of heat, cold or a significant change in heat production, it is possible to influence the value of the body surface temperature, thereby influencing the value of the temperature gradient between the body surface and the environment and the value of TC. Such reactions are vascular reactions - narrowing or dilation of superficial skin vessels. If vasodilation is not enough to increase heat transfer (in conditions of high external temperature), then sweating is stimulated, which creates additional opportunities to enhance heat by evaporating more moisture from the surface of the skin and lowering body temperature. Under conditions where, under the influence of cold, vasoconstriction is insufficient to reduce heat loss and prevent cooling of the body, physiological reactions of increasing TP are stimulated through contractile and non-contractile thermogenesis.
Radiation is a way of transferring heat from the surface of a body to the environment in the form of electromagnetic waves in the infrared range. The amount of heat dissipated by radiation into the environment is proportional to the surface area of the skin of those parts of the body that come into contact with the air. At an air temperature of 30–34 °C and a relative air humidity of 40–60%, the surface of the body of a naked child of the 1st month of life dissipates by radiation about 40% of the total heat given off. TO by radiation increases with a decrease in ambient temperature and/or an increase in skin temperature and decreases with an increase in ambient temperature and/or a decrease in skin temperature.
The skin of newborns and young children is well vascularized, and due to the intense flow of heated blood to the surface of the body from the internal organs, the skin temperature in children is higher than in adults. In addition to a higher temperature gradient between the body surface and the external environment, children have a number of other factors that cause intense heat. This is twice the body surface area per 1 kg of body weight, small thickness of the skin and its low thermal insulation properties, especially if the subcutaneous fat layer is insufficient.
The maturation of heat regulation mechanisms in a child lags behind the development of heat production regulation mechanisms and is actually completed only by the age of 7–8 years. Earlier (by 6 months - 1 year), the mechanisms of regulation of TH through the reactions of superficial vessels mature, the nature of which can be judged at room temperature by the change in temperature difference on the chest and limbs of a naked child.
An increase in the functional activity of the sweat glands and the regulation of sweating develop in children at a later date. The delay in the development of mechanisms that control heat transfer, in comparison with the development of mechanisms for regulating heat production, means that if basic precautions are not observed or with the development of certain diseases, overheating of children in the first months and years of life is more likely than their hypothermia.
Conditions of overheating or hypothermia of a child's body are especially likely when the body comes into contact with an aqueous environment (baths) or with other physical bodies (cold operating table, etc.), when heat is dissipated through heat conduction. The intensity of heat treatment also depends on the temperature gradient of the contacting bodies, the area of the contacting surfaces, the time of thermal contact and the thermal conductivity of the contacting body. Dry air and adipose tissue are heat insulators, while wet clothing, humid air and water saturated with water vapor, on the contrary, are characterized by high thermal conductivity.
High rates of heat dissipation and overheating or hypothermia of the child's body are achieved when they transfer heat to convection currents of air or water. Naked children of the 1st month of life at an air temperature of 30–34 ° C give about 36% of their heat to convection air currents.
The high intensity of heat in children is also facilitated by the dissipation of heat through the evaporation of moisture from the surface of the body and from the mucous membrane of the respiratory tract. In children, a significant amount of moisture sweats through a thin layer of the epidermis of the skin and constantly evaporates from the surface of the skin (imperceptible perspiration). The total amount of heat dissipated by the naked body of a child due to the evaporation of water is, under normal conditions, about 24%. When the external temperature exceeds the average skin temperature, the body cannot release heat to the external environment by radiation, convection and conduction. Under these conditions, the body begins to absorb heat from the outside, and the only way to prevent it from overheating is to increase heat dissipation through sweating and evaporation of moisture from the surface of the body. Sweating begins in newborns when the rectal temperature rises to 37.2 ° C (sweating threshold) and reaches its greatest intensity after 35–40 minutes. In newborns, the density of sweat glands is higher than in adults, but their functionality is lower. A child's sweat glands can produce up to 57 ml of sweat per 1 kg of body weight per day, and an adult - up to 500 ml. With age, the temperature threshold for sweating decreases and the functional activity of the sweat glands increases.
Evaporation of moisture is possible as long as the ambient air humidity remains less than 100%. With intense sweating, high humidity and low air speed, when droplets of sweat, without having time to evaporate, merge and flow from the surface of the body, heat transfer by evaporation becomes less effective and overheating of the body may occur.
Blood circulation plays a decisive role in removing heat from internal organs and tissues that produce it in large quantities and preventing their overheating. Blood has a high heat capacity, and by increasing or weakening the blood flow directed to the surface tissues, heat is transferred to the surface of the body, warming or cooling it, and creating conditions for greater or lesser heat transfer to the environment.
The level of regulated body temperature is established in the body by the hypothalamic thermoregulation centers. It is most likely that the preoptic area is directly related to determining the value of the regulated temperature, the neurons of which are sensitive to small changes in local temperature, control and regulate all types of thermoregulatory reactions that occur when the temperature deviates from the set one. If the local temperature of the preoptic area deviates above the level set for regulation, for example, when the child’s motor activity increases, then thermoregulatory reactions will be initiated in the body, increasing heat transfer, contributing to a decrease in body temperature and returning the local temperature of the preoptic area to the value set for regulation (about 37 ° WITH). If the local temperature of the preoptic area drops below a set value, for example, when cooling during swimming, then thermoregulatory reactions will be initiated, reducing heat loss, and, if necessary, increasing heat production and helping to increase body temperature and return the temperature of the preoptic area to a given level. The preoptic region of the hypothalamus contains (about 30% of the total) heat-sensitive neurons that receive afferent signals through synaptic inputs from heat receptors in the skin and other tissues, and heat-insensitive neurons (about 60%) that receive afferent signals from cold receptors.
In both full-term and premature babies, skin receptors are well developed. The most sensitive area of thermoreception is the skin of the face. Since the neurons of the preoptic area are sensitive to both changes in local temperature and signals coming from thermoreceptors about the nature of temperature changes in the periphery, they integrate both of these types of information and, depending on the obtained value of the integral body temperature, send one or another signal to effector neurons, triggering thermoregulatory reactions.
Thus, heat-sensitive neurons, under conditions of thermally indifferent ambient temperature and a slight (> 0.011°C) increase in the local temperature of the preoptic area above 37°C, activate effector neurons through excitatory synapses, located in the posterior hypothalamus and triggering thermoregulatory reactions of heat transfer. At the same time, heat-sensitive neurons can, through inhibitory synapses, inhibit the activity of effector neurons that control the level of heat production in the body. When exposed to cold, afferent influx from cold receptors enters thermoinsensitive neurons, which, after their activation, can have an excitatory effect on effector neurons that trigger reactions to increase heat production, and at the same time can inhibit the activity of effector neurons that control the level of heat transfer, thereby reducing heat dissipation.
The maturation of the central hypothalamic mechanisms of thermoregulation in children can be judged by the establishment of the correct daily rhythm of body temperature, which occurs by 1.5–2 months of age. Hypoxia, intracranial trauma, infections affecting the central nervous system (CNS), as well as its anomalies, can cause dysfunction of the central thermoregulatory apparatus.
A large group of substances of endogenous origin (interleukins (IL) - IL-lp, IL-la, IL-6; tumor necrosis factor, interferon) or bacterial origin (lipopolysaccharides) can increase set point and cause an increase in body temperature. These substances are called endo- and exopyrogens, respectively. Endopyrogens are produced by blood leukocytes, tissue macrophages, and Kupffer cells of the liver in response to the appearance of endotoxins, bacterial pyrogens, and other stimulating factors in the body. Endopyrogens themselves, as well as stimulating the formation of active metabolites of arachidonic acid - prostaglandins of groups E and F, together with the latter penetrate the blood-brain barrier and have an inhibitory effect on the excitability of heat-sensitive neurons of the preoptic area and the anterior hypothalamus. At the same time, the frequency of impulse activity of heat-sensitive neurons decreases and equality of inhibitory and excitatory flows on efferent neurons is achieved at a higher temperature - the set point value increases.
The formation of a new, higher level of regulated body temperature initiates a chain of processes that underlie the development of one of the main manifestations of fever - an increase in body temperature. This increase in temperature is stimulated by the thermoregulatory center until the current and target temperature levels are equal. After the formation of a higher set point value, normal body temperature begins to be perceived as lower than the set one and, as a result, mechanisms of accelerated heat production are activated (increased thermoregulatory muscle tone, muscle tremors) and mechanisms that reduce the intensity of heat transfer (constriction of skin blood vessels, acceptance of posture that reduces body surface area). At this time, a person feels chills, although the body temperature does not decrease, but rises and soon reaches a new set point. From this moment, the thermoregulation center again balances the values of TP and TO, trembling disappears, superficial vessels dilate, skin temperature rises, a surge of warmth is felt and chills disappear. Thermoregulation mechanisms continue to function normally, but body temperature is regulated at a higher level.
With successful drug relief of the fever, which is achieved by decreasing the set point value, the current higher temperature can be reduced by intensifying heat transfer. This is usually achieved by turning on mechanisms for stimulating sweating, which continues in the process of decreasing body temperature until it becomes equal to the new set point value.
Hyperthermia of various origins, unlike a febrile state, is not a consequence of an increase in the level of set point. Hyperthermia develops when the intensity of heat production exceeds the body's ability to release the produced heat into the environment, in particular, under conditions of high external temperature and high humidity. An increase in body temperature during hyperthermia of non-febrile origin occurs despite the efforts of the central and peripheral thermoregulation mechanisms to maintain normal body temperature.
The fetus, located in the mother's womb at a relatively constant body temperature, does not need its own thermoregulation. The heat that is generated by the fetal body is transferred through the placenta to the mother's blood, and the temperature of the blood flowing from the fetus to the placenta is 0.3–0.5 ° C higher than the blood flowing to the fetus. The value of fetal TP before birth is about 10–15% of the maternal TP.
Body temperature (rectal) in a healthy newborn is 37.7–38.2 °C, which is 0.1–0.6 °C higher than the mother’s body temperature. In children born prematurely, asphyxiated or injured at birth, there is a significant decrease in body temperature, which can persist for several days. A decrease in temperature to 35°C or more, its late return to normal levels and significant subsequent fluctuations in body temperature usually indicate a failure of thermoregulatory mechanisms.
Over the next few hours after birth, body temperature in healthy newborns drops by 1.5–2°C. The degree of decrease in body temperature is influenced by the weight of the child, the size of his body, the amount of vernix, and the conditions for caring for the newborn. In healthy children, body temperature soon begins to rise and after 12–24 hours reaches 36–37°C. Axillary temperature at birth is about 37.2 °C, after 2-3 hours it drops to 35.7 °C, by the 4th-5th hour it gradually rises to 36.5 °C, and by the 5th day of life - to 37°C. Typically, in the first days of life, a healthy newborn experiences temperature instability and rapid changes during swaddling and after feeding. Over the next few days, the body temperature of newborns remains unstable, gradually (by 1.5–3 months) the temperature curve characteristic of healthy infants is established. For a long time, the body temperature in children is usually 0.3–0.4 ° C higher than in adults, and only gradually reaches the level of adults. A decrease in temperature in the first hours after birth is called transient hypothermia of newborns. It is caused by the effect of a lower ambient temperature than in the womb and the immaturity of thermoregulation mechanisms. In children born physiologically immature and/or premature, as well as in patients, more pronounced hypothermia is observed, which persists for several days.
Rectal temperature in children is usually 0.3–0.5 °C higher than skin temperature measured in the armpit or groin area. After physical exercise, especially after running, long walks and other exercise, there is a temporary increase in rectal temperature in children, more than in the axillary, and the temperature difference in these areas can reach 1°C or more. In this case, in children there is a local rather than a general increase in body temperature. The higher rectal temperature is explained by abundant blood flow in this area, the proximity of large muscle masses that produce heat, and heat production by bacterial microflora.
The pattern of daily fluctuations in body temperature, or circadian rhythm, varies among children, but is relatively constant within an individual. The circadian rhythm is absent in newborns and young children and is established after the second year of life. In children it is more pronounced than in adults. The lowest body temperature is observed around 3 a.m., and the highest - from 5 to 6 p.m. The difference between the highest and lowest points of the temperature cycle in children is greater than in adults. This difference in children can reach 1 °C. Daily temperature fluctuations are more significant in girls than in boys. The range of temperature fluctuations during the day at a stable ambient temperature in the first days of life is about 0.3°C, by 2–3 months. increases to 0.6°C and by 3–5 years - up to 1°C. The magnitude of fluctuations in body temperature depends not only on age, but also on environmental temperature, physical activity, the emotional state of the child, the quality and quantity of food taken, the functional state of the endocrine system, as well as other factors affecting basal metabolism, physical activity, vascular tone . The clinical significance of the circadian rhythm is multifaceted. Knowledge of normal daily temperature changes helps the doctor avoid misinterpreting the causes of a moderate physiological increase in evening temperature and perceiving it as a manifestation of hyperthermia or fever. The same applies to discussions about subnormal temperatures in the early morning hours.
Cyclic daily fluctuations in body temperature in a healthy child are established by 1.5–2 months. life, which coincides in time with the formation of daily rhythms of heart contractions and respiratory rates. In premature infants, the daily cycle of temperature is established much later than in full-term infants. The preservation of a normal circadian rhythm of temperature in children with brain diseases may indicate that the central mechanisms of thermoregulation are not damaged.
The relative insufficiency of heat production in newborns, and especially premature infants, requires the creation of an optimal temperature environment for them - a thermoneutral zone. Its boundaries are the range of air temperature surrounding the child, at which normal body temperature is maintained with minimal tension on the TP mechanisms. If for healthy naked newborns born at term, the boundaries of the thermoneutral zone are 32–35°C, then for a very premature baby it is 35–36°C. For swaddled newborns, the temperature boundaries of this zone shift to 23–26°C and 30–33°C, respectively. By the age of one month, the temperature indicators of the thermoneutral zone shift down by 1.5–2°C, and the width of their range increases by 0.3–0.5°C.
In a small proportion of newborns (0.3–0.5%), on the 3rd–5th day of life, a rise in body temperature to 38–39 °C is observed, lasting from several hours to one day. This condition, called transient hyperthermia, is likely due to some dehydration of the newborn and a reaction to colonization of the intestines by microorganisms.
In healthy newborn children, there is practically no decrease in body temperature below 36–36.1°C. A decrease in temperature below this level usually reflects a failure of energy metabolism and is observed, as a rule, with malnutrition, severe cardiac and vascular failure, insufficiency of liver and kidney function, decreased function of the thyroid gland, adrenal glands, hypoglycemia and other serious diseases.
Changes in body temperature in children can be caused by various reasons. Prolonged exposure to cold or heat may be uncompensated by insufficiently mature thermoregulation mechanisms and lead to a significant increase (exogenous hyperthermia) or decrease (exogenous hypothermia) in body temperature, which often occurs in premature and immature children.
Newborns easily overheat when the air temperature rises, which is due to their low body weight, the proximity of the temperature of the thermal indifferent zone and body temperature, and the low functional activity of the sweat glands. Overheating is also caused by excessively restricting heat transfer by clothing.
When exposed to low air temperatures in newborns, heat production increases, but the intensity of this reaction is often insufficient to maintain normal body temperature, especially with prolonged exposure to cold. The maximum increase in heat production in newborns does not exceed twice the value of the basal metabolism (in an adult, heat production during cooling can increase for a short time by 3–4 times).
Thus, among the most important features of thermoregulation in newborns we can highlight: a higher level of heat transfer in relation to heat production; limited ability to increase heat transfer during overheating, as well as to increase heat production during cooling; inability to respond with a feverish temperature reaction due to the weak sensitivity of hypothalamic neurons to the action of leukocyte and other endopyrogens and the high concentration of arginine vasopressin in the blood, which reduces body temperature. A feature of thermoregulation in newborns is the absence of reactions of increased thermoregulatory tone and cold shivering when body temperature decreases. When rapidly cooling, they experience a variety of uncoordinated movements, accompanied by screaming. This reaction serves as a signal to the mother to eliminate exposure to cold.
Thermoregulation reactions in premature babies are even more imperfect, so these children are placed in incubators, in which, depending on the period of prematurity and the body weight of the child, a certain temperature is automatically maintained. A premature baby weighing 1300 g per 1 kg of body weight accounts for about 0.09 m 2 of its surface, which is 3.75 times more than in adults and 1.4 times more than in full-term newborns. Lower (about 2 times) heat production in premature babies, thinned skin, poorly developed subcutaneous fatty tissue, which do not provide normal thermal insulation of the body, are the reason that the thermoneutral zone of these children is at the level of 35–36 ° C. Even a slight excess of this temperature in the external environment leads to overheating of the child, and a decrease leads to hypothermia. In premature babies born before the 7th month of intrauterine development, there is no sweating, and in newborns with a lesser degree of prematurity (body weight 1.8–2.2 kg), sweating is observed immediately after birth, but its functionality is low.
The criteria for the maturity of the thermoregulation system are considered to be the presence of a child’s relative constancy of rectal temperature at an air temperature of 20–22 °C; the difference between the rectal temperature and the temperature in the armpit or between the temperature of the skin on the chest and on the feet; daily periodicity of body temperature; temperature reaction in infectious diseases.
In terms of the level of development of thermoregulation, a newborn child is considered homeothermic, however, the range of fluctuations in external temperatures within which the relative constancy of body temperature is maintained is narrower than in older children. In premature newborns it is even more narrowed.
Thermometry is a mandatory component of patient examination. Body temperature is most often measured in the armpit in compliance with the accepted rules (skin should be dry, hand pressed, exposure 5–10 minutes), less often - in the rectum or oral cavity. The latter method is rarely used in our medical institutions, although it is very widespread abroad. Taking into account the circadian rhythm, temperature is measured in the morning (7–8 o'clock - minimum phase) and early evening hours (18–19 o'clock - maximum phase). Daily temperature fluctuations in healthy people usually do not exceed 0.6°C (36.2–36.8°C). If necessary, in particular in the diagnosis of septic conditions, fractional thermometry is prescribed with temperature measurements every 3 hours (patients should not be woken up at night) in order to identify additional temperature peaks. In the diagnosis of neurotic conditions, the presence and severity of temperature asymmetries are also assessed according to simultaneous measurements in the left and right armpits.
Normally, when the average body temperature deviates by a small amount from the set value, the existing differences are easily compensated by changing the intensity of heat transfer without a significant change in heat production, which is achieved through sympathetic influences on the lumen of the blood vessels of the body surface and, as a result, more or less heat transfer by the blood from the “ core" of the body to the "shell" and its dispersion by physical mechanisms. If, despite the increase in heat transfer, the level of integral body temperature exceeds the set temperature, a sharp increase in sweating occurs. The evaporation of moisture from the surface of the body and behavioral reactions acquire leading importance in enhancing heat transfer.
If the intensity of heat production exceeds the body's ability to release heat to the environment, hyperthermia occurs. The likelihood of hyperthermia increases when the body is exposed to external temperature, at 100% air humidity, when the evaporation of sweat or moisture from the surface of the body becomes impossible. In case of prolonged hyperthermia, heat stroke may develop.
It has been established that in adults the mechanism of temperature rise during fever involves mainly limiting heat transfer. In infants, the most significant role is played by the enhancement of non-shivering thermogenesis in brown fat (located in Bichat's lumps, interscapular region, in the mediastinum, along the aorta and large vessels, along the spine and sympathetic trunk, in the abdominal cavity, behind the sternum, around the kidneys and adrenal glands; quickly depleted by the end of the neonatal period) and other organs under catecholamine influence. Warming the spinal oscillator area with warm blood flowing from adjacent brown fat prevents tremors. Fever for a child is a more energy-intensive process than for an adult, so young children quickly lose weight when they have a fever. Intensive lipolysis increases the risk of ketoacidosis and aggravates the clinical manifestations of fever.
The following periods are distinguished in the development of febrile conditions:
Statum incrementi (first stage of fever) - with a typical course and moderate severity, lasts no more than 3–4 hours from the start of metabolic processes;
Statum fastigii (stage of standing temperature, acmatic phase) - means that a new set point has been reached. At the height of this stage, thermoregulation is carried out by mechanisms similar to the norm. Heat production and heat transfer are balanced, the patient is neither hot nor cold; skin vessels are dilated, skin temperature has increased, chills and trembling have disappeared; breathing is rapid; diuresis is reduced. According to the temperature during this phase, fever is subfebrile (up to 38 °C), mild (up to 38.5 °C), moderate (up to 39 °C), high (up to 41 °C), hyperpyretic (above 41 °C) . The duration of the acmatic phase can vary from several hours to several weeks; - Statum decrementi (stage of extinction, temperature drop) - occurs when exogenous pyrogens are exhausted, endogenous production ceases and under the influence of natural or iatrogenic antipyretics. At this stage, heat transfer sharply increases, since the set point shifts downward, and the skin temperature and blood temperature are perceived by the hypothalamus as increased. Intense sweating, perspiration and diuresis are stimulated. The decrease in temperature can be gradual, lytic (within several days) and rapid, critical (within 1–2 hours), while a sharp expansion of skin blood vessels can be complicated by collapse. However, the classic 3-phase cycle is now characteristic of untreated fever and is rarely observed.
Questions about the benefits and harms of fever and, accordingly, the volume of necessary antipyretic therapy are resolved in each specific case individually, taking into account the constitutional characteristics of the child, premorbid background and the nature of the underlying disease. It is important to consider that the decrease in temperature is not a simple consequence of the exhaustion of the pyrogen resource, but has the nature of an active reaction controlled by natural antipyretics. These may include some hormones, such as arginine vasopressin, adrenocorticotropin, a-melanocyte-stimulating hormone, corticoliberin and glucocorticoids. Many aspects of the acute phase response are inhibited by somatostatin and endogenous opioid and barbiturate receptor agonists (endorphins, enkephalins).
In febrile conditions, the ideal should be the selection of drugs that, while minimizing the unfavorable symptoms of fever or hyperthermia, do not disrupt the course of physiological processes. In addition, it must be recalled that the main criterion for choosing antipyretic drugs in children is safety and effectiveness. Based on this situation, currently only ibuprofen and paracetamol fully meet the criteria of safety and effectiveness and are officially recommended by the World Health Organization for use in pediatric practice as antipyretics. They are approved in Ukraine for over-the-counter use and can be prescribed to children from the first months of life both in a hospital and at home.
The drug paracetamol has an antipyretic, analgesic and very weak anti-inflammatory effect, since it implements its mechanism of action (inhibits the synthesis of prostaglandins by blocking cyclooxygenase) mainly in the central nervous system and does not have a peripheral effect. Ibuprofen (form for young children - Nurofen for children) has more pronounced antipyretic, analgesic and anti-inflammatory effects, which are determined by its peripheral and central mechanisms.
Nurofen for children has a pronounced antipyretic, analgesic and anti-inflammatory effect. Based on materials from the works of E. Autret et al. , the antipyretic effect of ibuprofen at a dose of 7.5 mg/kg is higher than that of paracetamol at a dose of 10 mg/kg. This was manifested by a greater decrease in temperature after 4 hours and in a larger number of children. The same data were obtained in a double-blind study in parallel groups with repeated administration of Nurofen for children 7 and 10 mg/kg and paracetamol 10 mg/kg in children over 5 months. up to 13 years old.
In almost all children with fever, a single dose of Nurofen for children leads to a decrease in body temperature by 1–1.5 °C and the disappearance of pain. In sick children at risk, when the drug was prescribed at a body temperature of less than 39.0 °C, the antipyretic effect of Nurofen for children develops 30 minutes after its administration. Over the course of 1.5 hours, an approximately uniform decrease in body temperature was recorded, amounting to a total of 3.9% of the initial elevated body temperature. It was noted that within 90 minutes in all children in this group after using Nurofen for children, body temperature decreased to 37.0–37.2 °C.
When the initial body temperature in children is above 39.0 °C, after taking Nurofen for children, a more intense, but not as uniform, decrease in fever is observed. Thus, 30 minutes after taking the drug, a decrease in body temperature by 1–1.5 °C is observed in 58.3% of children, after 60 minutes - in 86.1%, after 90 minutes - in 94.4%.
Nurofen for children blocks the activity of the cyclooxygenase enzyme both in the central nervous system and at the site of inflammation (peripheral mechanism), which determines not only the antipyretic, but also the anti-inflammatory effect. As a result, the phagocytic production of acute phase mediators, including IL-1 (endogenous pyrogen), decreases. A decrease in IL-1 concentration also helps normalize temperature. Nurofen for children exhibits a double analgesic effect - peripheral and central. The analgesic effect is already evident at a dose of 5 mg/kg and is more pronounced than that of paracetamol. This makes it possible to effectively use Nurofen for children with mild to moderate sore throat, pain with tonsillitis, acute otitis media, toothache, pain during teething in infants, as well as for the relief of post-vaccination reactions.
1 ml of Nurofen suspension for children contains 20 mg of ibuprofen. Nurofen for children is used from 3 months of life, 5 ml of the drug contains 100 mg of ibuprofen. A single dose is 5–10 mg/kg of the child’s body weight 3–4 times a day. The maximum daily dose should not exceed 30 mg per kg of body weight of the child per day.
The positive side of using Nurofen for children is its fairly persistent antipyretic effect. In most cases, after relief of hyperthermia, low-grade fever, or body temperature within the range of 37–37.8 °C, persists for 2–3 hours. A repeated rise in body temperature was the basis for further use of the drug. Nurofen for children in the form of a suspension is well tolerated, safe and has a pleasant taste. It should be noted that with its short-term use the risk of developing undesirable effects is quite low.
Thus, Nurofen suspension for children is very effective for relieving fever in children of the first year of life. The drug has a good antipyretic effect, is tolerable and safe. The persistent and long-lasting effect of Nurofen for children allows us to recognize it as a highly effective treatment for colds accompanied by hyperthermic syndrome. In recent years, Nurofen for children has been recommended for children as one of the main antipyretic drugs.
Literature
1. Kostenko A.Yu., Generalova G.A., Alimova E.Yu., Klyuchnikov S.O. Fever and hyperthermia in children / Edited by V.F. Demina, S.O. Klyuchnikova, G.A. Samsa-gynoy. - RGMU, 2002. - T. 2. - P. 367-382.
2. Korovina N.A., Zakharova I.N., Zaplatnikov A.L. Acute fever in children // RMZh. - 2005. - T. 13, No. 17. - P. 1165-1170.
3. Tatochenko V.K. Child with fever // Attending physician. - 2005. - No. 1. - P. 16-20.
4. Yulish E.I. Pathogenetic aspects of fever in children, indications and methods of its relief // Child’s Health. - 2009. - No. 4. - P. 26-30.
5. Autret E. et al. Evaluation of ibuprofen versus aspirin and paracetamol on efficacy and comfort in children with fever // Eur. J. Clin. - 1997. - 51. - 367-371.
6. Sidler J. et al. A double-blind comparison of ibuprofen and paracetamol in juvenile pyrexia //
Br. J. Clin. Pract. - 1990. - 44 (Suppl. 70). - 22-25.
7. Lebedeva R.N., Nikoda V.V. Pharmacotherapy of acute pain. - M.: AIR-ART, 1998. - P. 184.
8. Bertin L., Pons G. et al. Randomized, double-blind, multicenler, controlled trial of ibuprofen versus acetaminophen (paracetamol) and placebo for treatment of symptoms of tonsillitis and pharyngitis in children // J. Pediatr. - 1991. - 119(5). - 811-4.
9. Tatochenko V.K. On the safe use of antipyretics in children // Children's Doctor. - 1999. - No. 2. - P. 36-37.
10. Vetrov V.P., Dlin V.V., Osmanov I.M. and others. Rational use of antipyretics in children. - M.: Moscow Research Institute of Pediatrics and Pediatric Surgery, 2000. - 22 p.
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A newborn baby is so tiny, so fragile, tender and touching that you want to protect him all the time, do something for him. This instinct is designed to protect the baby, but in our civilized times it often greatly harms the child’s health. A typical picture in the maternity hospital: a temperature of 24 degrees and a bag of a baby, a diaper, a suit or bodysuit, and two diapers. In more gentle cases, they are limited to a suit, a hat and a blanket. As a result, many babies come home with red and prickly skin. I admit, my first child arrived exactly like this.
Why is it necessary to harden children from the first days of life?
Your most wonderful baby in the world lived in your tummy in warmth and comfort. His body did not bother to deal with the issues of hydration, cleansing, heating and cooling. But now he was born and many different sensations and problems fell upon his body. And your main task is to teach all the body systems of your little miracle to quickly and adequately react in order to be able to protect themselves.
All three of my children got sick only once in the first year of their lives, and that was because I infected them. But, surprisingly, while I suffered with laryngitis for two weeks, they were sick for no more than a week. After a year, their illnesses were limited to a slight runny nose, maybe a cough, about twice a year. I never worry about their clothes - let them at least walk naked on the street if they are not cold, I never forbade them to climb in puddles in the spring, at home they only walk barefoot, without socks, without slippers, some in pants and a jacket, someone in only shorts. At the same time, our house is no more than 18 degrees.
I was raised according to standard rules - warm clothes, a warm hat, warm shelter, fear of drafts. Under these seemingly optimal conditions, I managed to end up in the hospital with pneumonia at the age of three. Throughout my childhood, as long as I can remember, I was sick. When I was a teenager I came with chronic tonsillitis. And now I get sick an order of magnitude longer and more severely than they do, and I freeze much faster than them. I didn’t want this for my children, so I taught their body to react correctly to the cold already in the maternity hospital.
How does thermoregulation work in babies?
A newborn baby is born with an effective thermoregulation system, it just differs from the system of an adult. This was done by nature specifically so that the baby has the opportunity to form a new system of thermoregulation and immunity from scratch, ideally suited to the conditions in which he will live. If you constantly wrap up a child and he is on the verge of overheating, then this new system is formed as if he were living in some equatorial climate. The body will not cope well with cooling, which will constantly affect the immune system. Hence the frequent colds.
So, in a newborn, brown subcutaneous adipose tissue, which is located between the shoulder blades, on the chest, on the neck, and near individual organs, is responsible for heating the body. It is formed from the 26th week of pregnancy specifically for the moment when the miracle of birth occurs. If the baby is cold, then the processes of fat oxidation with the release of energy begin to actively occur in this adipose tissue - the body heats up. A simple but effective mechanism for heat production.
If brown adipose tissue cannot cope, then the ability of muscle tissue to create heat during work comes into play. The baby wakes up, begins to cry and move actively. If this does not help, then after all the reserves of nutrients in the body are depleted, the newborn becomes silent, stops moving, the body begins to quickly cool down and death may occur.
But there are not many opportunities to combat overheating. The sweat glands still work poorly, and the layer of clothing prevents the sweat from evaporating. But it is completely impossible to stop the production of heat, because it is produced all the time as a result of many oxidative reactions occurring in the body. These reactions are necessary for cells to receive nutrition, to create new cells, and for the transition of one substance to another. Heat is also released from the constant movement inside his body - blood moves, internal organs move, cells move.
An overheated baby becomes inactive, hot, wet, and does not even have the strength to cry. After all, now his body saves on movements. If he is not helped, then the body begins to collapse and everything can end in death. In milder forms, we observe overheating in the form of prickly heat or a sudden illness.
As an infant grows, the thermoregulation system changes and becomes similar to that of adults. The hypothalamus matures and takes on the responsibility of maintaining a constant body temperature. He now has a wide range of tools at his disposal: the creation of subcutaneous fat, hormones, nutrients from the digestive system, sweat glands, muscles, etc. So, the task of parents is to teach the hypothalamus to master these tools perfectly. To do this, you need to harden the child from the first days.
How to harden?
In general, there are many hardening methods. You choose the method that suits you best due to your lifestyle and living conditions. But there are several general rules that must be followed regardless of the technique:
- If a newborn is cold, his nasolabial triangle turns blue, he screams, twists his arms and legs, he may begin to tremble, and his thighs feel cool to the touch. But the nose, arms and legs should normally be cool, because... they are wet all the time.
- If the baby is hot, then his back, neck, armpits become wet, his face and body turn red, he becomes lethargic and sleepy. When severely overheated, the baby can go into hibernation for several hours, which allows him to reduce all reactions in the body.
- Any hardening procedure should not cause a crying attack in the child. If you lower the temperature in the bath and the baby begins to cry, then quickly take it out and calm it down, and next time lower it a little less.
I did something like this:
In the maternity hospital itself, we were all forced to measure the babies’ temperatures, and in the first days after the first baby’s arrival from the hospital, I regularly measured his temperature to know how it changed depending on how I dressed him. I determined the well-being of the second and third child with my hand and vision.
There is no need to put a cap on your head if the room temperature is above 20 degrees. In the maternity hospital they looked at me askance, because my children (except for the first) lay in a light suit and without a cap (the temperature in our room was 24 degrees), and after changing the diaper for some time they lay completely naked on the diaper - airing out.
When changing a diaper, do not rush to dress your baby - let the skin breathe a little. The blood vessels of the body learn to narrow in order to save heat. At our house the temperature was about 22 degrees, but in the village it was 18 - 19 degrees - they still lay there naked.
If it’s 30 degrees or higher outside, then you don’t need a blanket or a closed suit for a walk. It is best for the baby to ride in his stroller in only a diaper. The diaper can also be unfastened to prevent the perineum from sweating.
There is no need to wash your baby in water with a temperature above 36 degrees. It is better to gradually reduce the temperature, bringing it to 28 degrees. I haven’t even washed newborns at 37 degrees. I have never boiled water. I only added potassium permanganate in the first two weeks.
At the end of bathing, pour cold water into the bathtub from the legs to lower the temperature in the bathtub - this contrast procedure is more gentle than dousing it with cool water. I lowered the babies into the bath in a diaper - this way they were less scared and rarely flinched from the cool water. After lowering, the diaper simply sank to the bottom.
Komarovsky describes hardening quite well in his books, but there are other less fashionable methods. Although I didn't follow his books as clear instructions.
In general, in hardening, I have always been of the opinion (and still am): if he feels normal, does not complain, then he is not cold. My second child was born at the end of May, and in mid-June the swimming season began - we also circled his body in the water in the river (there were a lot of sidelong glances). By the way, during pregnancy I did not deny myself the pleasure of swimming in the river, even in the last months (the eldest was born in mid-September). Although I have never seen pregnant women swimming in a pond. So I admit that I am the only one.
At any ambient temperature, in the polar regions and in the tropics, the temperature of the human body is the same. In healthy people it does not exceed 37˚C. This is due to complex thermoregulation mechanisms.
Maintaining a constant body temperature is a function of many body systems. The skin also takes part in this process.
In the process of thermoregulation, two sides are distinguished - heat production and heat transfer. An increase or decrease in heat production is associated with an increase or decrease in the level of metabolism in body tissues. The more intense the metabolism, the more heat is generated in the body. When the ambient temperature increases, heat production decreases, and when it decreases, it increases. However, excess heat is always formed in the body. It is released into the environment through the skin.
Features of thermoregulation in children
A child's body temperature in the first months of life is not completely constant. It can change under the influence of various factors: cooling or overheating of bodies, eating, screaming, etc. This process depends on a number of reasons. First of all, the skin surface of a child relative to its mass is much larger than that of adults. Thus, in newborns there is 700 cm 2 of skin per 1 kg of body weight, in ten-year-old children - 425 cm 2, and in adults - 220 cm 2. It is clear that the younger the child, the more intense heat transfer occurs. The increase in heat transfer is also facilitated by the fact that in children the network of blood vessels penetrating the skin is much denser than in adults. These features are most pronounced in infancy. Vasomotor responses to heat and cold in infants are almost the same. Therefore, thermoregulation in infants is imperfect. That is why they must be protected from cooling and overheating.