physiological responses

Last reviewed 01/2018

There are two key physiological mechanisms for increasing heat loss from the body of Man:

  • sweating
  • vasodilatation

Generally, both act in tandem to lower core temperature under the integration of the hypothalamus. However, there may be situations when either mechanism is inefficient or disordered e.g. high external humidity or anticholinergic drugs for sweating, and the use of alpha-adrenoceptor blocking drugs for vasodilatation.

Decreased heat production is a theoretical means of decreasing temperature. In practice, the metabolic rate is unchanged; the only contribution to decreasing temperature is an inhibition of shivering and non-shivering thermogenesis. This is not as important as sweating and vasodilatation.