In order for the body to carry on its function efficiently its need energy. This energy is obtained through process is called combustion. The fuel for their combustion is the food that we take in. The result of combustion in the body is not, of course, a fire or enormous heat. It is a mind, exactly regulated warmth. There are substances in the body whose job it is to combine oxygen with the fuel in an orderly, controlled.
The body maintains an average temperature regardless of what is going on outside. This is done by the centre in the brain known as the temperature centre, which really consist of three parts: a control centre which regulates the temperature of the blood, one that raises the temperature of the blood when it drops, and a third that cool the blood when the temperature is too high.
When we shiver it is the body’s automatic reaction to the temperature of our blood dropping too low. Shivering actually produced heat!