Durations of Safe Exposure for Men at Work in High Temperature Environments

Abstract

Times taken to reach a state of imminent heat collapse were examined in a sample of 87 fit, unacclimatized young men dressed in overalls. Subjects wore required to perform a routine of continuous work at approximately 310 J/s in environmental conditions within the range 37·0/30·0°c to 83·4/4l·2°c dry-bulb/wet-bulb temperature in which air movement was either 0·76m/s or 1·02 m/s and air and wall temperatures were equivalent.

From the analysis of 440 observations, a general equation expressing a rectangular hyperbolic relationship between imminent heat collapse times and environmental Severity, described in terms of 0·22661 dry-bulb-+-0·77339 wet-bulb temperature in °c, was derived. On the basis of this equation lower confidence limits for individual observations were calculated as recommendations of safe exposure times from 120 mins to 10 mins. The durations of safe exposure presented are intended to protect from imminent heat collapse 75%, 90%, 95% or 99% of exposes from populations represented by the samples of subjects studied.

Additional information

Notes on contributors

C. R. BELL

Now at Department of Psychology, University of Manchester, Manchester, England.

M. J. CROWDER

Now at- Department of Mathematics, University of Surrey, Guildford, England.