Effects of thermal stress on human performance.

Experimental evidence indicates that even relatively mild thermal stress may affect human performance. Tasks requiring manual dexterity and muscular strength are clearly impaired by cold exposure, while decrements in vigilance performance and endurance are well documented effects of heat stress. The considerable variation in results regarding the effects of thermal stress may, to some extent, be attributable to complex interactions between exposure conditions, task characteristics, and individual factors. In the present paper the relevance of some of the earlier research work on heat and cold stress is evaluated in the light of the practical and theoretical implications of more recent findings. Current work regarding the nature and extent of the effects of thermal stress on more complex performance is discussed. Attention is also focused on the significance of individual skill and training experience for performance under unfavorable conditions.