What is the normal body temperature ?

To live and work the human body needs energy, which is obtained by burning the food we eat.
The result of the combustion of food in our body, of course, is not a big fire or heat. It's very mild, heat set correctly.
In the human body there are substances that combine oxygen with fuel in a predetermined manner.

What is the normal body temperature ?

Human body maintains a constant temperature between 36.6 ° C and 37 ° C (98.6F), regardless of the ambient temperature. 
This is accomplished through the center of the brain called “the center for maintaining body heat”.
It actually consists of three centers: one that monitors the temperature of blood, the other, which raises the temperature of the blood when it drops - center for conducting heat, and a third that allows cooling the blood when the temperature is too high – center for cooling.

What happens if the body temperature falls?

Part of the nervous system to maintain body heat is encouraged to take the action.
Then some glands secrete juices whose role is to increase the combustion of nutrients in the muscle and liver, and so the internal body heat rises.

At the same time, the skin blood vessels shrink, so that the radiation loses less heat.
Skin glands participate in this excretion with fatty substance that helps the body to retain heat.
Shaking occurs unconsciously, when the temperature of the blood falls too low.
Center for heat production in the brain makes us tremble in order to produce the more heat!
If the body temperature rises, the center of the cooling starts working.
It widens the blood vessels in the skin, so that excess heat radiation leaves the body.
In addition, cooling of the body is achieved with sweating.