At what temperature will people freeze to death when they fall asleep?

Lead: When the weather is cold in winter, I often hear such an blurted sentence: "This day is going to freeze to death." But the fact is that freezing to death also requires certain conditions. In particular, people have different physical reactions in extreme environments, so the chance of freezing to death is still very small. However, I heard that people can freeze to death when they are asleep. Then, at what temperature will people fall asleep and freeze to death? Let's take a look with Bian Xiao.

A few degrees of sleep can freeze people to death.

Whether a person will freeze to death is not directly related to the temperature in the area where the person is located. The main reason is that if people's own body temperature is too low, especially the rectal temperature is too low, it is likely to freeze people to death. For example, a person accidentally falls into the water. In this case, the human body will gradually cool down. Once the rectal temperature drops below 35 degrees Celsius, people will lose the ability to regulate their body temperature, their limbs will be weak and collapse, and then they will begin to be unconscious and hallucinate.

If the rectal temperature drops below 30 degrees Celsius, people will lose their will, pulse disorder, blood pressure drop, and finally die. Therefore, when the human body temperature is below 30 degrees Celsius, people will freeze to death.

Low ambient temperature accelerates the heat dissipation of human body, and the body maintains constant body temperature through body temperature regulation mechanism or artificial method. If the heat dissipation is greater than the heat generation, the body temperature will gradually drop and even die. The process of freezing to death can be divided into four stages: excitement stage, weakness stage, inhibition stage and complete paralysis stage. Each period is not completely separate, but continuous.

1. Body temperature during the excitation period is 36℃ ~ 35℃. At the beginning of a cold, chills appear, breathing and heartbeat are accelerated, blood pressure is raised, and nerves are in an excited state. During this period, more heat can be generated to maintain a lower body temperature.

2. When the body temperature is between 35℃ and 30℃, the excitement is weakened, the blood circulation and respiratory function are gradually weakened, breathing and heart rate are slowed down, and blood pressure is lowered. There may be burnout, inflexibility and consciousness disorder. Newborns and heart patients are prone to death during this period and last for a long time.

3. During the inhibition period, the body temperature is between 30℃ and 26℃, the heart rate, respiration and blood pressure gradually decrease, and the response to external stimuli is slow, and the consciousness is in a hazy state. At this stage, the body surface temperature and anal temperature are close to or equal to each other for a period of time, resulting in "abnormal heat sensation" and "abnormal undressing". Due to the enhancement of capillary permeability, interstitial edema, visceral congestion, decreased circulating blood volume, decreased cardiac output, shortened refractory period of cardiac conduction system and death of ventricular fibrillation.

4. When completely paralyzed, the body temperature is below 25℃, the thermoregulatory center fails, breathing and heartbeat are inhibited, blood pressure drops almost linearly, various reflexes disappear, and there is no response to external stimuli. Eventually, the vascular motor center and respiratory center were paralyzed and died.

The normal temperature of a person is 37℃. Hypothermia means that the victim's core temperature drops to 35℃. If the body temperature drops below 32℃, the situation will become serious and eventually fatal. About human body temperature, there are two opposite factors interacting. Low temperature, strong wind, and wet underwear make people chill. Only exercise and trembling can make the body generate heat. Clothes, shelter and fat layer can prevent heat loss, but will not produce heat.

Sweating lowers body temperature by evaporation. Trembling in the cold generates heat by increasing the chemical reaction required for muscle activity. Tremor can increase body surface heat production by as much as 500%, but it can only be effective within a few hours, because it will eventually lead to excessive glucose reduction and muscle fatigue.

In the cold and windy mountainous area, after exhaustion, it is necessary to cool down and wear wet underwear when it gets dark. If it is cotton underwear, the clothes are not warm enough, and there is no hat and gloves, you will not exercise after lying down. At this time, the factors of heating and heat preservation are less than those of long-term heat dissipation, which may lead to hypothermia.