Normal body temperature for human beings is around 37 degrees Celsius. Like all other mammals and animals that are warm blooded, humans regulate their core body temperature no matter what the external temperature.
They use various mechanisms to do this. Some are behavioural – putting extra clothes on when the weather gets cold and wearing fewer clothes when the weather is very hot. Others are physiological.
When body temperature starts to fall, blood vessels in the skin start to retract, burying themselves deeper beneath the skin and the layer of insulating fat that lies just beneath it. This cuts down the amount of heat that is lost through the skin and helps the body temperature to rise back to normal as heat is produced in the cells and the liver as a biproduct of metabolic reactions.
When body temperature starts to rise, even by a fraction of a degree, the opposite happens. Blood vessels in the skin start to come closer to the surface so that more heat can be lost. More sweat is also produced and, as this evaporates from the skin, the cooling effect helps to lower body temperature back to normal.
They use various mechanisms to do this. Some are behavioural – putting extra clothes on when the weather gets cold and wearing fewer clothes when the weather is very hot. Others are physiological.
When body temperature starts to fall, blood vessels in the skin start to retract, burying themselves deeper beneath the skin and the layer of insulating fat that lies just beneath it. This cuts down the amount of heat that is lost through the skin and helps the body temperature to rise back to normal as heat is produced in the cells and the liver as a biproduct of metabolic reactions.
When body temperature starts to rise, even by a fraction of a degree, the opposite happens. Blood vessels in the skin start to come closer to the surface so that more heat can be lost. More sweat is also produced and, as this evaporates from the skin, the cooling effect helps to lower body temperature back to normal.