Decision making in thermally stressful environments.

The literature on investigations into effects of thermal stress of psychological performance is reviewed in order to hypothesize ways in which functions of a decision-making process may be affected by exposure of a decision maker to hot and cold environmental conditions. A theoretical model is described relating psycho-physiological strain, associated with exposure to environmental thermal stress, to efficiency of performance of psychological tasks, categorized in terms of demands made on the human operator. From the evidence available, it appears that three aspects of decision making may be vulnerable to adverse effects of thermal stress. The initiation of the process of decision making may occur less reliably when cold or heat stress leads to signals, which may be serving as decision-making process prompts, being missed. Cognitive operations relating to information processing and evaluative procedures may be subject to decrements in efficiency when conducted in thermally stressful conditions. Thirdly, actions intending to implement decisions taken may be less effectively performed in thermally extreme environments.