Recent studies that provided information relevant to the recommendations made by the 1972 Criteria for a Recommended Standard on Occupational Exposure to Hot Environments, were reviewed. The emphasis was on the environmental index used (wet bulb globe temperature or wet globe temperature), allowable heat exposure, differences between males and females, the use of body temperature or heart rate to establish the physiological limit of exposure to heat, effects of age, protective clothing and acclimatization, loss and reinduction of acclimatization to heat, water requirements to compensate for body weight dehydration and salt requirements. The work practices recommended by the American Conference of Government Hygienists, regarding the work to rest ratio, which would allow the workers to retain their jobs and the industry to operate without loss of productivity under excessive hot conditions, were outlined. The author concludes that the results of the studies reviewed support some of the recommendations of the criteria document, raise questions about some others, and suggest the development of a more rational standard which would not require the shutdown of industrial facilities, while encouraging the elimination of thermal stress from the work environment.
Proceedings of a NIOSH Workshop on Recommended Heat Stress Standards, September 17-19, 1979, Cincinnati, Ohio