United Hatzalah

Hypothermia and Preserving Body Heat

Body heat is in effect the balance between the body heat we produce and the heat we emit in various ways. The body’s temperature is on average 37 degrees Celsius. The human body constantly produces heat and usually the temperature exceeds 37 degrees, but we nevertheless retain a balanced body heat. On the other hand, even when the outdoor environment is colder than usual, we still manage to maintain the basic body temperature of 37 degrees. All this is a result of special body heat balancing mechanisms located in the hypothalamus (part of the brain) whose function is to maintain the balance between excess heat (hyperthermia) and lack of heat (hypothermia).

There are several types of mechanisms which produce body heat. These systems, when properly functioning, will produce and maintain a balanced body temperature. When functioning excessively, they are liable to cause heat stroke (hyperthermia) and when they fail to function, they may cause frostbite (hypothermia).

  • The muscular-skeletal system produces the most body heat via energy production and constant activity. The hypothalamus recognizes when we get cold and activates the muscles’ heating system in the form of vibrations and movements in order to produce heat and balance the body’s temperature. On the other side of the coin, strenuous exercise — or excess activity of the muscular-skeletal system — can cause hyperthermia, as can be seen during trips, exercise, and various sports competitions. In addition, even after routine exercise, the body reaches very high temperatures after muscle activity and it takes a long time to return to the normal range.
  • Another organ that produces a large amount of heat is the liver. The liver is a large metabolic organ in the abdominal cavity and its main function is to allow enormous amounts of blood to undergo various metabolic processes. These processes require energy which produces a great amount of heat. In addition, the large amounts of warm blood flowing through it make it the hottest organ in the human body. Therefore, a decrease in liver function will cause the body temperature to drop, as in patients suffering from cirrhosis or viral hepatitis.
  • The blood system has an important function in maintaining body heat. In cases of hypothermia, the blood vessels contract, which causes heat to be maintained deep down within the skin and fat tissue, thereby less blood is exposed to the outside temperature and this preserves the body heat so it won’t be emitted. This is why we may turn pale in cold weather. In cases of hyperthermia, (excess heat), the blood vessels expand in order to move as much blood as possible to peripheral areas and transfer heat out of the body. And that is why we may turn red in the cold.
  • There are many additional mechanisms which can affect the level of heat preservation, production and heat loss, such as: age, physical structure, muscle mass, fat percentage, hormone levels, changes in the biological clock, stressful situations and more….

Why is heat preservation so important?

When the body reaches a state of hyperthermia— extreme temperature elevation, by definition above 40 degrees Celsius — proteins in the body are exposed to heat and undergo a process known as denaturation. This is a process by which the protein changes its spatial structure; it hardens and disintegrates until it is no longer active. Since proteins are an integral part of normal body function, any damage to them constitutes an immediate threat to life.

When the body reaches a state of hypothermia — extreme temperature reduction, by definition below 35 degrees Celsius — body processes begin to slow down. To be more specific: bradycardia (slow heart rate) to the point of asystole (flatline, or no heart activity), bradypnea (abnormally slow breathing), decrease in metabolic processes, decrease in various hormonal and enzyme activity and, in fact, all functioning of vital body organs such as the pancreas, liver, kidneys and spleen. This slowing down of functioning may result in a deep coma, or worse, death.


In case of emergency dial 1221

Popular Posts

To Top