Medical expert of the article
New publications
General hypothermia
Last reviewed: 07.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
General hypothermia causes a complex compensatory reaction in the form of reflex vasospasm, increased heat production by the liver, activation of the heart and blood flow, and the biochemical process of glycolysis. When the body temperature drops below 30°, a sharp decompensation occurs with increased heat loss due to paralytic vasodilation. Glycolysis is completely depleted. The survival rate of the organism when exposed to cold is quite low. In a condition such as general hypothermia, a person can survive 6 hours in water with a temperature of 15°, 1 hour at 10°, 30 minutes at 1°.
The severity is determined by the temperature in the rectum. Its maintenance up to 35° is defined as general hypothermia of the body, its decrease to 25° is defined as general hypothermia, and a decrease below 25° is assessed as freezing.
The body's reaction to general hypothermia occurs in stages, defining 4 stages of freezing.
- Stage 1 - compensatory. Clinically, general hypothermia is manifested by agitation, chills, muscle tremors. The skin is pale, cyanosis of the lips and acrocyanosis, "goose bumps". Blood pressure is elevated, pulse and breathing are rapid. Hypertonicity of muscles is noted. Temperature in the rectum up to 35°.
- Stage 2 - adynamic. The victim is conscious, but inhibited, euphoric, has headache, dizziness, weakness. General hypothermia is characterized by adynamia, decreased muscle reflexes. Blood pressure is normal, bradycardia up to 60-50 per minute. Breathing is preserved, but tachypnea up to 40 per minute. Rectal temperature is reduced to 35-30°.
- Stage 3 - soporous. Lethargy, apathy, drowsiness, memory disorders, dysarthria, and a false sensation of warmth are observed. Hypertonicity of muscles is characteristic. Pupils are dilated. There may be urinary and fecal incontinence. Blood pressure is sharply reduced, pulse is 30-50 per minute. Respiration rate is 8-10 per minute. Rectal temperature is 29-25°.
- Stage 4 - comatose. Consciousness is absent. Involuntary movements of the head, limbs, slightly opening eyes, trismus, tension of the abdominal muscles and limbs are noted. The pupils are constricted, there is no reaction to light, the corneal reflex is absent, the eyeballs are floating. Blood pressure is sharply reduced, the pulse is weak, up to 20 per minute. Breathing is within 3-5 per minute. The temperature in the rectum is 25 °, a lethal outcome from paralytic cardiac and respiratory arrest quickly occurs, in which resuscitation measures are absolutely ineffective.
In all types of frostbite and rigor, the victim should be hospitalized in a surgical department, usually in a purulent-septic department. During transportation, warm the limb by wrapping it up and rub it dry with a mitten or warm hands.