Du Fu has a poem: "Zhumen's wine and meat stink, and the road has frozen bones." It's freezing. People's body temperature is too low. They will really freeze to death.
If the human body is exposed to extremely cold temperatures and lacks thermal insulation facilities, the heat production of the body is not enough to resist the low temperature of the environment, and the body temperature will continue to decline. After reaching a certain degree, the activity of cells in the whole body will weaken and gradually lose their function. When the body temperature is lower than 35 ℃, various functions of the human body begin to disorder. When the body temperature is lower than 25 ℃, the regulation function of hypothalamus is completely lost, and then the respiratory and heartbeat centers begin to fail and paralyze, and people die in coma.
Some diseases can also cause hypothermia. Under the conditions of shock, advanced cancer, old age, severe weakness and long-term severe hunger, the human body will lack calories and the body temperature will be lower than normal due to malnutrition or excessive nutritional consumption. This low temperature may be the body's self-protection mechanism, not a bad thing; However, if the body temperature continues to drop, it indicates systemic failure with serious consequences. Hypothermia is also clinically significant. For example, the use of mild hypothermia in the operation of patients with brain injury can greatly reduce brain damage and improve the survival rate by reducing the patient's body temperature to about 35 ℃.