We all know that man is warm blooded. The normal body temperature of man always remains stable. The external environment does not affect the body temperature of man. 98.6 degrees F or 37 degrees C is the normal temperature of a healthy person. Because of this temperature our body remains warm. Let us study from where the heat energy comes in our body and keep it warm.
The food we eat regularly gives heat energy to our body. Heat is produced in our body by the food substances due to the process of oxidation. Oxidation is a type of combustion. We know that heat is also produced by the burning of fuel. In burning of fuel both light and heat is produced, whereas no light is produced when oxidation of food takes place. To perform different types of work, our body use heat that we get from food. Everyday our body produces about 2500 calories of heat energy to keep us warm and helps our body to do different types of work.
The ‘temperature centre’ of brain helps to maintain the body temperature. It consists of three parts: control centre, heating centre and the cooling centre. The function of the control centre is to regulate the blood temperature, heating centre helps to raise the blood temperature when it falls and the cooling centre helps to cool the blood temperature when it rises. When the temperature centre of the brain gets disturb then our body starts shivering and it causes fever. If the heating centre gets disturb, it leads to shivering whereas the disturbance in cooling centre leads to fever in the body. Heat is always radiated out from the body, this is the reason why the things on which we sit or sleep gets warm.