The human body is set to a temperature of 37.5° whether it is hot or cold outside and it hardly ever changes. It turns out that the secret of this thermoregulation is at the level of our brain!
This secret resides in a part of the brain called the hypothalamus, a gland barely the size of a walnut. The latter assumes the role of a thermostat, regardless of the ambient temperature.
Indeed, when it is very hot, this gland forces the blood vessels to dilate, which will cause our skin to sweat. This allows our body to cool off and evacuate excess heat. On the other hand, when the temperatures are cold, the messages sent are intended for the muscles which contract in order to produce heat and dedicated to making our hairs stand up which then represent a barrier to the cold.
37.5° is therefore a good temperature, ideal for ensuring optimal functioning of our cells, the exact term for this process being “biochemical compromise”. Its variations are therefore rather rare: the time of day when it is lowest is in the morning when you wake up and when the 37.5° are exceeded, the fever begins. This represents an alert indicating that the body is defending itself against an infection. The temperature can rise up to 43°, but rarely beyond. In 1980, an American named Willie Jones still survived a temperature of 46.5°!
The lowest threshold that the body temperature can reach by proving dangerous is from 28° and up to 24°. This is called severe hypothermia. This represents 1% of the number of deaths attributable to cold in temperate countries.
Animals – especially cold-blooded ones – have a different functioning from ours and therefore a temperature that is also different. For example, ectotherms (snakes and lizards) have a temperature that can go up to plus or minus 20°. For mammals, differences are also notable: dogs have a body temperature between 38.5° and 39°, while birds are rather between 40° and 42°, but the tit beats records with its 44° .
Sources: Le Figaro — Allo Docteurs