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The decrease in body temperature to a level dangerous to life and health is called hypothermia. It mainly develops as a result of exposure to freezing temperatures after exposure to the cold without the protection provided by warm clothing. Hypothermia can occur in any person when a number of negative factors coincide.
Before hypothermia of its own core (heart and blood vessels), the human body makes attempts to correct the situation: trembling occurs, signals are sent to the brain. After the body temperature drops to a critical level, the metabolic rate drops sharply, the life support of organs stops, without which a person can temporarily exist. If the danger of hypothermia persists for more than two hours in a row (in severe frost this period is significantly reduced), as well as in those who suffer from a serious illness or from blood loss, the chances of a successful outcome are small. A frozen person feels very tired, and if he falls, he will no longer be able to get up.
Lack of help is not an indispensable condition for death from hypothermia – while the body is in a state of suspended animation, there are chances for salvation. If, however, the wrong warming tactics are used, then, oddly enough, this can lead a frozen person to death much sooner.
13 facts about hypothermia
Important facts about hypothermia:
It is not necessary to be exposed to -30° frost to get hypothermia. Even a positive temperature below +10° can be fatal if you stay outdoors in wet clothes for a long time, undergo chemotherapy or radiation before that, and also lose more than 0,7 liters of blood.
In a state of intoxication, people are most often exposed to hypothermia.
Body temperature is regulated by the hypothalamus, the main gland of the human endocrine system.
In addition to the hypothalamus, the spinal cord is responsible for thermoregulation, as well as the medulla oblongata and midbrain located in the final part of the brain. If their functions are impaired as a result of any pathology, hypothermia can occur much faster even at positive air temperatures.
Staying motionless in frost at -35 ° is accompanied by a decrease in body temperature by 1 ° every half hour.
If apathy sets in, unwillingness to go in search of help, then the body temperature has dropped to 32,9 °.
If the stiffness of the joints is felt, the movements of the limbs are limited, therefore, the body temperature has dropped below 32,2 °.
Upon reaching the mark of 31,1 °, trembling disappears, with the help of which the body doubles the amount of heat produced. However, at this stage, even such a waste of energy is unjustified.
If a freezing person fell, having lost his last strength, he usually does not remember anything from that moment, because the body turns off the areas of the cerebral cortex responsible for memory from saving.
Hypothermia is extremely dangerous for children from 1 month to 6 years old, because their thermoregulatory system is not yet perfect.
Hypothermia for newborns is not as dangerous as for adults, although they do not experience a shivering reaction. As a defense, the body uses brown adipose tissue, which is available in excess in the baby’s body for up to 28 days. It is located in the projection of the shoulders, back, neck, surrounds the kidneys.
Brown adipose tissue is present in a small amount in an adult, it produces heat in emergency cases. This tissue is formed during intense physical exertion.
If a freezing person experiences a sensation of heat, he is close to agony and death.
If the body temperature has reached 24 °, irreversible changes have occurred in the body. However, during open heart surgery, the patient’s temperature is artificially lowered to 20°C for a short time in order to be able to perform surgical manipulations within 17 minutes with the heart-lung machine turned off.
Measures taken by the body to adapt to hypothermia:
Trembling due to muscle contraction – increases several times the amount of heat in the human body, raises the temperature of the contracting muscle by 2 °. Physical activity increases the release of heat 2-2,5 times more intense than shivering.
Increasing the amount of energy needed for the activity of the main thermoregulatory body. The main load associated with life support processes falls on the thyroid gland, therefore, in people with a history of hypothyroidism, hypothermia occurs much faster;
Energy consumption of lipid tissue (overweight people are less likely to suffer from hypothermia);
Acceleration of metabolism in the liver, leading to an increase in the amount of energy for the life support of the body;
Increased heart rate, leading to an increase in the amount of heat;
Inclusion in the processes of life support of areas of the renal and brain tissue;
Reducing the area of contact of the body surface with the environment (folding into a “ball”);
Deterioration of the blood supply to the skin, muscles of the limbs, subcutaneous tissue, sweat glands, which increase the evaporation of heat;
Reducing the frequency of respiratory movements that waste heat;
Atavism in the form of “goosebumps”, “goosebumps”, a kind of “raising wool”, the purpose of which is to create a layer of warm air around the body.
Causes of hypothermia
Causes of hypothermia:
Negative air temperature;
High humidity;
High wind speed (at 5 m/s, heat evaporates from the skin 2 times faster, at 10 m/s – 4 times faster);
Out-of-season clothing, refusal to wear hats, gloves;
Shoes that do not fit, or are made of rubber, or have too thin soles;
Wearing synthetic clothes in the cold season;
Prolonged immobility in the open air;
Intoxication, in which the vessels are dilated, due to which the warm blood coming from the heart quickly cools on the periphery, and then cools the heart and internal organs, in addition, the reactions of the central nervous system are slowed down, and a drunk person can fall asleep in the open air and not wake up .
Factors that increase the risk of hypothermia:
Following a strict and unbalanced diet;
Deficiency of vitamins in the diet;
Chronic fatigue;
Long-acting stress;
Constantly reduced pressure;
Long-term somatic or infectious disease, leading to emaciation, lack of adipose and muscle tissue;
History of heart failure, as the blood thickens in the cold and it is difficult for the heart to pump it;
The presence of cancer;
Adrenal insufficiency (Addison’s disease), one of the symptoms of which is low blood pressure, which reduces the rate of blood circulation;
HIV – infection;
Hypothyroidism, due to which the activity of the thyroid gland, which is responsible for maintaining normal body temperature, is reduced;
Cirrhosis of the liver, in which the functional tissue of the organ is replaced by fibrous fibers;
Acute and sudden loss of blood, to which the body does not have time to develop a compensatory response;
Traumatic brain injury with loss of consciousness.
Symptoms and degrees of hypothermia
The clinical picture of hypothermia depends on body temperature. At 36,0-36,1°, the muscles are tense, ready for trembling, which contributes to the replenishment of heat reserves. A plan of salvation is formed in a clear consciousness, and a person is preparing to implement it, he has a fear of freezing. This stage is not yet hypothermia, but early rewarming is already necessary.
When cooled to 35 °, panic seizes a person, trembling appears throughout the body. Muscles lose flexibility and obedience, knees almost do not bend, hands freeze. After warming, such muscle tension becomes the cause of pain. This stage is not yet hypothermia.
In stage 2, the muscles stiffen, harden, and pain occurs due to excessive stimulation of the nerve endings. While this stage has not yet arisen, a person possessed by panic fear tries to escape and get to the warmth. As long as he has not yet fallen, and the clothes are not soaked with sweat and retain their tightness, a freezing person still has a chance to survive.
There are four degrees of hypothermia:
1 degree. At the dynamic stage, the body temperature is reduced to 34-32°. A person becomes covered with “goosebumps”, vasospasm makes it pale. Movements slow down, limbs bend badly. Respiratory rate and heart rate decrease, blood pressure falls. The clarity of consciousness is lost, the person commits illogical acts. In place of panic comes indifference and fatigue.
2 degree. At the stage of stupor, the body temperature drops to 29 °. The trembling stops, drowsiness sets in. The heart rate drops to 50 beats per minute, arrhythmia appears, and it is difficult for the heart to pump thick blood. Movement is impossible, consciousness is clouded, hallucinations occur. The kidneys work, but with great strain, because all the blood is in the central vessels, the peripheral vessels are empty. Perhaps uncontrolled urination, aggravating the severity of the situation. At a temperature of 29,4 ° there is a feeling of heat, when a person feels that he is being warmed, and he begins to undress. This is the so-called “paradoxical undressing”.
3 degree. The body temperature drops to 25°, there is a sudden clearing of consciousness, and then it fades away. With a superficial coma, there is almost no reaction to painful stimuli, the eyes are closed. The heart rate is about 40 beats per minute, the breathing is shallow, the skin is bluish, swollen. Vomiting is fixed, convulsions may occur.
4 degree. The convulsive stage is considered irreversible, although there are examples when people survived even after a decrease in body temperature to 16 °. Symptoms of the fourth stage – a drop in temperature below 24 °, the depletion of the body’s defense mechanisms. The skin is waxy, blue-yellow, the body and limbs are difficult to unbend, there is periodically a strong cramp. A deep coma is expressed in the absence of a reaction to an appeal to a freezing person, slapping him on the cheeks. The pupils are dilated, breathing is rare and irregular. Heart rate – 20-25 beats per minute.
First aid for hypothermia
In the case of a slight hypothermia of the child after a winter walk, when his limbs are cold, but he does not worry and retains his appetite, warming occurs in the following sequence:
Warm water is drawn into the bath (37-38 °);
Cold clothes are removed from the child, covered with a blanket.
Rub the body and limbs under the covers with warm hands.
Warm drinks or milk formula are offered.
Put the baby in warm water for 20 minutes.
Wipe dry, put on warm clothes that are not a child.
Similarly, older children and adults can be kept warm.
Rules for first aid in severe cases:
Warming must be carried out gradually, because with rapid warming, blood from the brain rushes into the suddenly expanded capillaries, and it ceases to be supplied with blood due to a sharp decrease in pressure.
They begin to help a frozen person, even if there are no signs of life, because the slowdown of chemical reactions from the cold can show the death of a person, although he is still alive.
First aid algorithm:
Take off wet clothes, remove snow, ice from the body.
Call for emergency assistance, indicating the reason for the call.
Wrap the freezing person in a warm blanket, put on a hat and mittens.
When moving a person into a room, do not unbend his body, bent into the fetal position.
When convulsions appear, insert a small cloth roller into the mouth that does not block breathing.
In the absence of a pulse, perform an indirect heart massage and artificial respiration – alternating 30 chest compressions with 2 breaths into the mouth or nose of the resuscitated person.
If possible, measure body temperature by rectal method.
Do not feed or drink the victim to avoid intestinal ischemia.
In case of mild hypothermia, give warm tea, broth, water to drink.
The victim, who is conscious, is placed on the area of large vessels with bottles of warm water.
You can not put a frozen person in a very hot bath to avoid shock due to a sharp expansion of the capillaries.
Prohibited procedures for acute hypothermia:
Straightening bent joints with sharp movements;
Rubbing with snow, only massage with warm hands is allowed;
Pouring a hot liquid into the mouth of an unconscious person, as well as trying to give the victim alcohol to drink;
Dousing with hot water or taking a hot bath.
Treatment of hypothermia in the hospital
Of course, a person with signs of hypothermia, found unconscious and with minimal signs of life, should be sent to the hospital.
There are other good reasons for hospitalization for hypothermia:
Hypothermia of a child or an elderly person;
Determination of arrhythmic pulse;
The presence of signs of frostbite of any, even minimal degree, especially if there is a history of diabetes mellitus, obliterating endarteritis, trophic ulcers, atherosclerosis of the lower extremities;
Marked 2-4 stage of hypothermia;
Algorithm for providing medical care:
A person who has suffered from hypothermia is placed on a mattress filled with warm water.
Solutions heated to 37 ° C or slightly higher are administered intravenously.
To ensure full breathing, patients are given a mask with humidified oxygen, if they are unconscious, they are injected into a therapeutic sleep with an injection of Sibazon and sodium oxybutyrate, then they are transferred to artificial respiration using a mechanical ventilation apparatus.
According to indications, defibrillation is carried out.
An obligatory measure when restoring the patient’s vital activity in the 3rd stage of hypothermia is to connect him to a heart-lung machine, which raises the body temperature by 3° every 1 minutes. In difficult cases, an operation is performed to wash the internal organs with warm saline.
The introduction of drugs that stimulate cardiac activity.
Installation of an artificial pacemaker that provides defibrillation of the ventricles.
Prevention of vasospasm by the introduction of antispasmodics after the restoration of the heart rhythm.
The introduction of painkillers with the appearance of pain after frostbite and vasospasm.
Stimulation of heart nutrition with vitamins and antihistamines.
After the arrival of a frozen person in the hospital, doctors use an electronic sensor placed in the rectum to monitor body temperature. Its decrease in the first time after warming a person is considered the norm, because cold skin and subcutaneous tissue cool the entire body and internal organs. With the correct introduction of warm saline every 15 minutes, the body temperature rises by 1 °.
At the same time, monitoring of heart rate, blood pressure, and respiratory rate is carried out. To do this, perform an ECG or install a heart monitor to monitor the heart rhythm.
Possible complications
Hypothermia leads to very serious consequences:
Frostbite of limbs and other parts of the body;
Pneumonia;
Influenza, SARS;
ENT diseases;
Exacerbation of existing somatic pathologies.
Death as a result of hypothermia can occur from excessively rapid warming, ventricular fibrillation, cardiac arrest, frostbite of the extremities in the last stage.
It may not be hypothermia of the whole body, but hypothermia of its individual parts or organs. With hypothermia of the head, vasospasm occurs, leading to headache and dizziness. It is required to undergo a course of therapeutic treatment.
Consequences of hypothermia of the head:
Meningitis:
ARVI;
Inflammation of the sinuses;
Aggravation of the course of hypertension;
Hearing loss due to inflammation of the inner ear;
Inflammation of the trigeminal or facial nerve.
Complications as a result of hypothermia of the legs:
Adnexitis;
Cystitis;
Pyelonephritis;
Articular pathologies;
Frostbite of limbs;
Colds.
With hypothermia of the lower back, sciatica, inflammation of the tissues of the kidneys, and prostatitis can develop. Hypothermia of the trigeminal nerve and its branches that innervate the teeth leads to an inflammatory process, accompanied by very strong twitching pain. With complications of this process, physiotherapy and pain medication therapy under the guidance of a neurologist is required.
Hypothermia of the tooth leads to the appearance of granulomas – capsules with pus on the root. Its symptoms are swelling of the gums and its redness. The disease requires the help of a dentist.
Hypothermia in children
Hypothermia does not always develop in children after being outdoors in insufficiently warm clothing.
Causes of hypothermia in childhood:
Delay in changing wet diapers;
Decreased air temperature in the room despite the fact that the child is not dressed warmly enough;
Bathing the baby in cold water;
Prolonged exposure to air in cold and damp weather.
In a private house, a child can be left unattended and go outside. The likelihood of hypothermia increases in children suffering from anemia and rickets, as well as in insufficiently and uniformly fed babies.
Symptoms of hypothermia in children:
Weakness, drowsiness;
Rapid breathing and tachycardia;
Low skin temperature;
Atypical behavior – silence, excessive calmness in a previously active child.
Until the age of 3, children do not have muscle tremors, as a reaction to hypothermia. Important measures to save a hypothermic child are wrapping him up, calling for emergency help, changing clothes, applying heating pads from small plastic bottles to large vessels.
Preventive measures
Basic rules for preventing hypothermia:
Outerwear should be warm and dry, it is better if it is made of fur and natural fabrics.
Dress for the weather, wear a hat and gloves.
Alcohol in the cold season is better not to drink.
The skin on the hands and face during frost should be protected with a greasy cream.
Shoes should not be tight, it is better if they are not rubber. If you have to wear rubber boots in rainy weather, you should put a fleece or wool lining in them.
The sole of footwear for winter and autumn wear should not be thinner than 1 cm.
It is undesirable to carry hand luggage over a considerable distance during the cold; when the first signs of hypothermia appear, you should go to a cafe or a store in order to warm up.
When traveling by car alone, it is advisable to inform relatives and friends of the route and approximate time of arrival.
When driving off-road, it is better not to turn off the road, not to travel alone in winter.
If you get into drifts on the road, it is better not to leave the car until help arrives if the settlement is far away.
Before going outside in winter, you should eat a hearty meal.
It is advisable not to wear earrings and rings in cold weather, you can not walk in cool weather with wet hair.
To keep warm in the cold air, you can squat, run in place, walk fast.
If you’re cold, don’t be shy about asking other people for help.