The thermolysis consists of the whole of the systems concerned by the organizations homéothermes in order to dissipate the surpluses of heat and to maintain the Température interns stable (37°c for the man, 40°c for the dog).

In the thermal zone of comfort (between 18°c and 32°c for the Man) the heat produced by the Métabolisme compensates for exactly the losses of heat per radiation, convection, conduction and transpiration (insensitive sudation).

With the top of 32°c the cutaneous temperature becomes lower than the outside temperature. The exchanges by Radiation and Convection then constitute a profit of heat for the organization which must bring into play systems of thermolysis in order to keep the temperature interns with 37°c. At the man the only effective system of thermolysis is the Sudation. The sweat which wets the skin " emporte" with it a certain heat while evaporating. This mechanism is ineffective in water but also in the atmospheres saturated with moisture.

It is necessary to know that in a hot environment, there is vasodilation of the vessels, therefore hypotension and increase of the cardiac flow. the people having problems cardiac thus manages badly thermolysis