Each of us knows about the existence of such a thing as body temperature. In a healthy adult, its indicators should be in the range of 36-37 ° C. Deviations in one direction or another indicate the occurrence of a disease of any etiology or a violation of the thermoregulation of the body. This condition is not a disease, as such, but it can cause destabilization of the work of organs and systems, even lead to death. The ability to thermoregulate possess all warm-blooded mammals, including humans. This function was developed and fixed in the course of evolution. It coordinates metabolic processes, makes it possible to adapt to the conditions of the outside world, thereby helping living organisms fight for their existence. Each individual, regardless of species, status or age, is exposed to the environment every second, and dozens of different reactions occur continuously in his body. All these processes provoke fluctuations in body temperature, which, if there were no thermoregulation that controls them, would lead to the destruction of individual organs and the whole organism. In principle, this happens when a violation of thermoregulation occurs. The causes of this pathology can be quite diverse, from trivial hypothermia to serious diseases of the central nervous system, thyroid or hypothalamus. If a person suffering from such ailments has a thermoregulation system that does poorly in its functions, in order to correct the situation, the underlying disease must be treated. If the thermoregulation is disturbed in a healthy person, and the reason for this is external conditions, such as weather, you need to be able to provide first aid to such an injured person. Often his further health and life depend on this. This article provides information on how the regulation of body temperature occurs, what symptoms indicate malfunctions in thermoregulation, and what actions should be taken in this case.
Body temperature features
Violation of thermoregulation is inextricably linked with body temperature. Most often, it is measured in the armpit, where it is normally assumed to be 36.6 ° C. This value is an indicator of heat transfer in the body and should be a biological constant.
Nevertheless, body temperature in small ranges can vary, for example, depending on the time of day, which is also the norm. Its lowest values are recorded between 2 and 4 o’clock in the morning, and the highest between 4 and 7 o’clock in the evening. In different parts of the body, temperature indicators also change, and this does not depend on the time of day. So, in the rectum, normal values are from 37.2 ° C to 37.5 ° C, and in the mouth from 36.5 ° C to 37.5 ° C. In addition, each organ has its temperature norm. It is highest in the liver, where it reaches 38 ° C to 40 ° C. But from climatic conditions, the temperature of the body of warm-blooded should not change. The role of thermoregulation is precisely to maintain it constant under any environmental conditions. In medicine, this phenomenon is called homeothermia, and constant temperature is called isothermia.
Violation of body thermoregulation is characterized by an increase or decrease in body temperature. There is a clear range of its upper and lower values, beyond which it is impossible to go, because it leads to death. With certain resuscitation measures, a person can survive if his body temperature drops to 25 ° C or rises to 42 ° C, although there are known cases of survival at more extreme values.
The concept of thermoregulation
Conventionally, the human body can be represented in the form of a certain core with a constant temperature, and a shell where it changes. In the core, processes occur, as a result of which heat is released. Through the shell between the external environment and the core, heat transfer occurs. The source of heat is the food we absorb daily. When processing food, the oxidation of fats, proteins, carbons, that is, a metabolic reaction, occurs. During their course, heat production is formed. The essence of thermoregulation is to maintain a balance between heat transfer and the formation of heat products. In other words, in order for the body temperature to stay within normal limits, the shell must give off the heat as much as it forms in the core. Violation of the body’s thermoregulation is observed when there is an over expenditure of heat production, or, conversely, it forms much more than the shell is able to remove to the environment.
This may be due to:
- environmental conditions (too hot or too cold);
- increased physical activity;
- clothing not suitable for the weather;
- taking certain medications;
- alcohol intake;
- the presence of diseases (vegetovascular dystonia, brain tumor, diabetes insipidus, various syndromes of hypothalamic dysfunction, thyrotoxic crisis, and others).
Thermoregulation is carried out in two ways:
1. Chemical.
2. Physical.
Let's consider them in more detail.
Chemical way
It is based on the relationship between the amount of heat generated in the body and the rate of exothermic reactions. The chemical type includes two methods of maintaining the desired temperature - contractile and non-contractile thermogenesis.
Contractile begins to act when you need to increase body temperature, for example, when you are in the cold. We notice this by raising hairs on the body or by running "goose bumps", which are microvibrations. They allow you to increase heat production up to 40%. With more severe freezing, we begin to tremble. It is also nothing more than a method of thermoregulation, in which the production of heat products increases by about 2.5 times. In addition to involuntary reflex reactions to the cold, a person, while moving, himself can raise the temperature in his body. Violation of thermoregulation in this case occurs when the exposure to cold is too long or the temperature of the medium is too low, as a result of which the activation of exchange reactions does not help to produce the right amount of heat. In medicine, this condition is called hypothermia.
Thermogenesis can be non-contractile, that is, take place without muscle involvement. Metabolism slows down or accelerates under the influence of certain medications, with increased production of hormones in the thyroid gland and in the adrenal medulla, with more active activity of the sympathetic nervous system. The reasons for the violation of human thermoregulation in this case lie in diseases of the above organs of the thyroid gland, central nervous system, impaired adrenal function. Information about temperature changes always comes to the central nervous system. The heat center is located in the tiny section of the diencephalon, the hypothalamus. It distinguishes the front region responsible for heat transfer, and the rear, responsible for the production of heat production. CNS pathologies or hypothalamic dysfunction disrupt the coordinated work of these parts, which negatively affects thermoregulation.
Thyroid hormones T3 and T4 also affect the intensity of heat transfer, and in addition, some functions of blood vessels. In the normal state, in order to save heat, the vessels are narrowed, and in order to reduce it, they expand. California scientists have proven that hormones can “interfere” with blood vessels, causing them to stop responding to the amount of heat produced and the body’s need for it. In medical practice, there is often a violation of thermoregulation in patients diagnosed with a brain tumor or thyrotoxic crisis.
Physical way
He performs the work of heat transfer to the environment, which is carried out by several methods:
1. Radiation. It is characteristic of all bodies and objects whose temperature is greater than zero. Radiation occurs by electromagnetic waves in the infrared range. At an ambient temperature of 20 ° C and humidity of about 60%, an adult loses up to 50% of his heat.
2. Conduction, which means heat loss when touching cold objects. It depends on the area of contacting surfaces and the duration of contact.
3. Convection, which means cooling the body with particles of the medium (air, water). Such particles touch the body, take away heat, heat up and rise up, giving way to new colder particles.
4. Evaporation. This is the familiar perspiration, as well as the evaporation of moisture from the mucous membranes during breathing.
In conditions of the impossibility of using these methods, a violation of the body's thermoregulation is observed. The reasons for this may be different. So, convection and conduction are hindered or reduced to zero if a person is wrapped in clothes that exclude contact with air or any objects, and evaporation is impossible at 100% humidity. On the other hand, significant activation of heat transfer also leads to a violation of thermoregulation. For example, convection increases in the wind and increases many times in cold water. This is one of the reasons why people, even those who know how to swim well, die in shipwrecks.
Thermoregulation in the elderly
Above, we examined what the thermoregulation of the human body and the causes of its violation, but without age-related features, are. However, in humans, the ability to control body temperature undergoes changes throughout life.
In the elderly, the mechanisms of the hypothalamus work, which evaluate the temperature of the environment. They do not immediately feel the cold while standing on the ice floor, nor do they immediately react to hot water, for example, in the shower. Therefore, they can easily harm themselves (supercool, burn themselves). It has been noticed that in elderly people who do not even complain about the cold, their mood spoils, causeless dissatisfaction appears, and when they create a comfortable climate, all these harmful “symptoms” of an old nature decrease or disappear.
At the same time, many old people freeze even at fairly comfortable air temperatures. They can often be seen on a warm summer day dressed in winter. Such changes in thermoregulation occur due to circulatory disorders and a decrease in hemoglobin levels.
Old people not only react to cold, but also react to heat in a slightly different way. At high ambient temperatures, their perspiration begins later, and the restoration of normal temperature indicators of the body is slower. In other words, the symptoms of hypothermia or overheating in them begin to appear later than in young people, and the recovery of the body is more difficult.
Violation of thermoregulation in a child
For a child's body, other features of the thermoregulation system are characteristic. In newborns, it is very imperfect. Infants are born with a body temperature in the range of 37.7 ° C - 38.2 ° C. After a few hours, it drops by about 2 ° C, and then reaches 37 ° C again, which should not cause concern. Higher rates can be a signal of the onset of a disease. The imperfection of the thermoregulation system in infants should be compensated by the creation of appropriate climatic conditions. So, up to 1 month in a nursery, the air temperature must be maintained at 32 ° C - 35 ° C if the baby is undressed, and 23 ° C - 26 ° C if he is swaddled. To stimulate thermoregulation, you need to start with the simplest thing - do not put a hat on the head. In children older than 1 month, these temperature standards decrease by about 2 ° C.
Children born prematurely have more serious problems with thermoregulation, therefore, in the first days, and sometimes even weeks, they are kept in special cuvettes. All manipulations with them, including the processing of the umbilical cord, washing and feeding, are also carried out in cuvettes.
The body’s control over temperature is only stabilized by the age of 8.
Violation of thermoregulation in a baby can occur for the following reasons:
- inhibitory effects on the hypothalamus (fetal hypoxia, birth hypoxia, intracranial injuries during obstetric care);
- congenital pathologies of the central nervous system;
- subcooling;
- overheating (excessive wrapping);
- drugs (beta blockers);
- change of climatic conditions (it happens when parents travel with babies).
In infants, the temperature measured in the armpit is considered normal in the range of 36.4 ° C to 37.5 ° C. Lower values may indicate dystrophy, vascular insufficiency. Higher values indicate inflammatory processes in the body.
Symptoms of a violation of thermoregulation with hypothermia
Depending on the cause of the interruptions in the control of body temperature, various signs are observed indicating a violation of the body's thermoregulation. Symptoms during hypothermia or hypothermia begin to manifest when the body temperature drops below 35 ° C. This condition can occur with prolonged exposure to frost or in water. For an average person, a water temperature in the range of 26-28 ° C is considered acceptable, that is, you can stay in it for a long time. With a decrease in these indicators, the time that can be in the aquatic environment without compromising health is sharply reduced. For example, at t = 18 ° C it does not exceed 30 minutes.
Hypothermia, depending on the complexity of the course, includes three stages:
- light (body temperature from 35 ° C to 34 ° C);
- medium (t = from 34 ° C to 30 ° C);
- heavy (t = 30 ° C to 25 ° C).
Symptoms with a mild form:
- goose-flesh;
- cyanosis;
- trembling body;
- rapid breathing;
- sometimes there is an increase in blood pressure values.
In the future, the violation of thermoregulation processes progresses.
The victim has the following symptoms:
- low blood pressure;
- bradycardia;
- rapid breathing;
- narrowing of the pupils;
- cessation of trembling in the body;
- the disappearance of pain sensitivity;
- inhibition of reflexes;
- loss of consciousness;
- coma.
Hypothermia Treatment
If, due to hypothermia, a violation of the body's thermoregulation has occurred, treatment should be aimed at increasing body temperature. With a mild form of hypothermia, it is enough to perform the following actions:
- go into a warm room;
- drink hot tea;
- rub your legs and put on warm socks;
- take a hot bath.
If there is no way to quickly get into the heat, you need to start active movements - jumping, rubbing your hands (just not with snow), pops, any physical exercises.
First aid in violation of thermoregulation of the second, and especially third degree should be provided by the closest people, since the victim himself can no longer take care of himself. Algorithm of actions:
- transfer a person to heat;
- quickly take off his clothes;
- rub the body with light movements;
- wrap in a blanket, and preferably in a fabric that does not allow air to pass through;
- if the swallowing reflex is not disturbed , drink with a warm liquid (tea, broth, water, but not alcohol!).
If possible, you need to call an ambulance and deliver the patient to a hospital, where treatment will be carried out using antispasmodics, analgesics, antihistamines and anti-inflammatory drugs, vitamins. In some cases, resuscitation measures are carried out, sometimes frostbite limbs have to be amputated.
In children, the occurrence of hypothermia is observed especially often. When undercooling, they need to be warmed up by wrapping, give breast or warm milk. An excellent means of stimulating thermoregulation is hardening, which parents should conduct the baby from the first months of life. In the initial stages, it consists in air baths and walks in the fresh air. In the future, rubbing the legs with a wet cloth, washing with cool water, bathing with a gradual decrease in the temperature of the water, walking barefoot are added.
Hyperthermia
A rise in body temperature or hyperthermia almost always causes a violation of the body's thermoregulation. The reasons may be the following:
- many diseases (injuries, infections, inflammations, vegetovascular dystonia);
- prolonged exposure to the sun;
- clothes that prevent perspiration;
- stress;
- increased physical activity;
- binge eating.
If the patient has signs of a disease (cough, gastrointestinal upset, complaints of pain in the organs and others), he should undergo a series of diagnostic tests to identify the cause of the fever:
- blood analysis;
- Analysis of urine;
- radiography;
- ECG;
- Ultrasound.
Having diagnosed, they carry out therapy of the revealed ailment, which simultaneously restores the body temperature to normal values.
If, due to overheating, a violation of thermoregulation occurs, treatment consists in creating conditions for the victim to restore the functioning of the body systems. When sunstroke, the following symptoms are observed:
- general malaise;
- headache;
- nausea;
- temperature rise;
- increased sweating;
- Sometimes there are cramps, loss of consciousness and nosebleeds.
The victim should be placed in a cool place (it is desirable to lay and raise his legs) and:
- if possible, undress;
- wipe the body with a damp cloth;
- put a cold compress on your forehead;
- drink cool salted water.
Heat stroke is of three types of intensity:
- mild (body temperature increased slightly);
- medium (t = from 39 ° C to 40 ° C);
- heavy (t = from 41 ° C to 42 ° C).
The mild form is manifested by headache, fatigue, fatigue, rapid breathing, tachycardia. As a treatment, you can take a cool shower, drink mineral water.
Violation of the thermoregulation of the human body in the middle form is manifested by the following symptoms:
- adynamia;
- nausea before vomiting;
- headache;
- tachycardia;
- sometimes loss of consciousness.
Symptoms of a severe form:
- confused consciousness ;
- cramps;
- the pulse is frequent filiform;
- breathing is frequent, shallow;
- the tone of the heart is dull;
- the skin is hot and dry;
- anuria;
- delusions and hallucinations;
- change in blood composition (decrease in chlorides, increase in urea and residual nitrogen).
In moderate and severe forms, intensive therapy is carried out, including injections of "Diprazin" or "Diazepam", according to indications, the introduction of analgesics, antipsychotics, cardiac glycosides. Before the ambulance arrives, the victim must be undressed, wiped with cold water, put ice in the groin, armpits, on the forehead and neck.
Thermoregulatory Disorder Syndrome
This pathology is observed with hypothalamic dysfunction and can manifest itself as hypo-and hyperthermia.
Causes:
- congenital pathologies;
- a tumor;
- intracranial infection;
- exposure to radiation;
- bulimia;
- anorexia;
- malnutrition;
- an excess of iron.
Symptoms
- patients equally badly withstand both cold and heat;
- constantly cold limbs;
- during the day the temperature remains unchanged;
- low-grade temperatures do not respond to antibiotics, glucocorticoids;
- lowering the temperature to normal values after sleep, after taking sedatives;
- the relationship of temperature fluctuations with psychoemotional stress;
- Other signs of hypothalamic dysfunction.
Treatment is carried out depending on the causes of the problems with the hypothalamus. In some cases, it is enough to prescribe the correct diet for the patient, in others hormone therapy is required, and in the third, surgical intervention.
Chills syndrome also indicates a violation of thermoregulation. Those who have this syndrome are constantly freezing, even in the summer. The temperature is often normal or slightly elevated, subfebrile condition lasts long and monotonous. Such people may experience sudden surges in pressure, increase heart rate, respiratory distress and excessive sweating, impairment of attraction and motivation. Studies show that the cause of chills is a disorder in the autonomic nervous system.