What is temperature regulation?

Thermoregulation is the regulation of the temperature in the body, i.e., the balance of heat gain and heat loss in order to maintain a constant internal body temperature independent to the external temperature. The internal temperature of humans is about 37ºC.

A constant internal temperature is important because:

• Metabolic processes require an optimal temperature

• At temperatures higher than 37ºC enzymes can begin to denature and stop to function – slowing metabolism

• At temperatures lower than 37ºC chemical reactions in the body start to slow (collision theory) – slowing metabolism

A rise of 2ºC will make a human feverish, and if the temperature reaches between 43ºC and 45ºC, death may occur. Our tolerance to lower temperatures is much greater, and temperatures need to fall below 23ºC for it to be fatal. Death results from metabolism slowing to a point where not enough energy is produced for the body to function.

The body responds in two different ways to deviations in temperature;

• Behavioural, where we consciously change our behaviour (what we do

• Physiological, where our body automatically changes its functioning without conscious control

What are thermoreceptors?

Thermoreceptors are a type of receptor found in the body which detect deviations in both internal and external body temperature.

Peripheral thermoreceptors are located in the skin and in some mucous membranes.

• Cold thermoreceptors detect reductions in internal body temperature

• Hot thermoreceptors detect a rise in internal body temperature

Central thermoreceptors are located in the hypothalamus.