A Meta-Analysis of Performance Under Thermal Stress

The goal of this work was to perform a quantitative review of temperature effects on human performance, with the aim of advancing both theory and practice. Meta-analytic methods were applied to the available literature on thermal stress and performance. Two-hundred-ninety-one references were collected resulting in forty-nine publications that met selection criteria. These studies provided 528 effect sizes. Analyses revealed an overall detrimental effect of temperature on performance. Effect-size for heat was comparable to that for cold temperatures. Temperature effects were task dependent, that is cognitive performance was least affected by thermal stress, while both psychomotor and perceptual task performance were degraded to a greater degree. Other moderating variables were identified and observed to influence the effect of thermal stress. Although the results clearly indicate more empirical research is necessary to achieve more accurate estimates, the current study provides initial effect-size estimates that should be considered when designing human-machine systems.