Visual and Auditory Vigilance During Exposure to Hot and Humid Conditions

The effect of exposure to climatic conditions ranging in severity from 29.5/24.5°C (85/76°F) db/wb to 63/47°c (145/117°F) db/wb on the performance of (1) a visual and (2) an auditory vigilance task was studied separately in two series of experiments on fit young men. Exposure time decreased with increasing climatic severity. When performance was examined in terms of the proportion of signals missed to signals given there was no evidence of a change in vigilance with different climatic conditions; but in both experimental series, a greater proportion of signals was missed as body (oral) temperature increased.