Psychological and physiological responses to raised body temperature

The performance of 12 male volunteers in an adding test and in a test requiring prolonged vigilance was measured at normal body temperature and while temperature was maintained at 37.3, 37.9, and 38.5 C. Each subject was measured at each level of body temperature on four occasions. Both the extent and the direction of the effect on performance varied with 1) the task being carried out, and 2) the degree of temperature elevation. Compared with performance at normal temperatures, the ability to add was impaired and vigilance was improved at 38.5 C. At 37.3 C, on the other hand, smaller changes reflected in general an improvement in adding and an impairment of vigilance. As a result of the repeated sessions of controlled hyperthermia, the subjects became heat acclimatized but there was no corresponding improvement in performance at raised body temperature, indicating the absence of short-term adaptation of the central nervous system functions tested to repeated elevations of body temperature.

hyperthermia; vigilance and addition performance in hyperthermia; heat acclimatization male Caucasians; psychomotor performance; heat tolerance; artificial acclimatization

Submitted on August 15, 1963