The Effects of Increased Ambient Temperature on Dual Task Performance

Abstract

This paper reports on the effects of two levels of increased ambient temperature on the performance of a tracking task and a variety of secondary mental tasks.

Significant performance decrements due to increased ambient temperature were observed for the least complex mental tasks. It must be concluded that for the intelligent, highly motivated subjects used in this experiment, simple tasks involving a minimum of mental effort are more sensitive to Effective Temperatures up to 32.2°C (90°F) for exposure times between one and two hours. It appears that complex mental tasks remain unaffected by ambient conditions that produce only minor changes in the physiological state, and may actually show small increases in performance level.

The performance improvement with increasing heat stress for difficult tasks and the corresponding decrement for simple tasks supports a theory that heat stress at the levels used in this study tends to decrease arousal. Based on an inverted-U performance curve, a lower level of arousal would result in the prediction of exactly the results obtained in this study.