Temperature Regulation, Heat Balance and Climatic Stress

Th is paper discusses human thermoregulation and how this relates to health problems during exposure to climatic stress. Th e heat exchange of the body with the environment is described in terms of the heat balance equation which determines whether the body heats up, remains at stable temperature, or cools. Inside the body the thermoregulatory control aims at creating the right conditions of heat loss to keep the body temperature stable. In the heat the main eff ector mechanism for this is sweating. Th e heat balance is aff ected by air temperature, radiant temperature, humidity and wind speed as climatic parameters and by activity rate, clothing insulation, and sweat capacity as personal parameters. Heat tolerance is discussed in the light of personal characteristics (age, gender, fi tness, acclimatisation, morphology and fat) indicating age and fi tness as most important predictors. Heat related mortality and morbidity are strongly linked to age.