Combined Effects of Altitude and High Temperature on Complex Performance

Abstract

Nine well-trained subjects were tested on a complex-performance device involving tracking, monitoring, and mental arithmetic during exposure to altitude (14,000 ft.) and heat (60° C) both singly and in combination. Several physiological measures were taken. Exposure durations were 30 min. for each condition with both pre- and posttesting. The only clear-cut effects of the conditions were significant differences across the environmental conditions on the tracking task. Altitude was clearly a more powerful variable than temperature in this study. This was evidenced by the fact that performance under the temperature-plus-altitude and the altitude-only conditions were approximately the same; performance under the temperature-only condition was significantly better than performance for either of the other two conditions. There was some evidence that the two environments in combination produced a persistent effect on performance that did not dissipate with return to normal conditions. Measured physiological functions of the subjects were within the tolerable range.