ABSTRACT
For aircrew, consequences of being unable to cope with thermal stress range from discomfort and subtle decrements in performance to illness and death. To maintain stable body temperature, heat exchange with environment by conduction, convection, radiation and evaporation must be balanced with metabolic heat production. Behavioural responses to hot and cold have a greater impact on heat balance than physiological responses. Significant imbalances in heat balance lead to a range of illnesses and injuries. Cold water immersion is an important thermal risk in aviation. Aircrew are routinely exposed to extreme thermal environments in air and occasionally in water. Core temperature is the primary input to physiological thermoregulation and influences core-to-skin heat transfer. Mean skin temperature is a modulator of physiological thermoregulation, the site of heat exchange with environment and influences core-to-skin heat transfer; dictates water vapour pressure at skin.
