The effectiveness of preventive work practices in a hot work shop.
NIOSH 1980 Dec; :32-45
Methods used to evaluate potential heat stress situations at the DuPont Company were reviewed and physiological determinations performed to confirm the adequacy of the controls installed. Air conditioned rest areas were found to be effective for controlling heat stress situations, but the assessment of hot jobs by thermal stress measurements, applying the currently recommended stress criteria which involve stress measurements and subjective evaluation of metabolic rate, was shown to be difficult and not fully protective. Evaluation of heat strain by measuring the heart rates and oral temperatures of the exposed individuals were found to be simple, although the respective criteria for excessive strain required confirmation to provide the guidelines for the employment of the workers according to their individual heat tolerance. Measurements of the heart rate recovery were also used to predict the onset of fatigue. A heart rate pattern classification scheme was developed for the evaluation of short term or long term hot jobs. High heart rate recovery patterns were shown to be indicative of work at high metabolic levels, with little accumulated body heat, while no recovery patterns were indicative of excessive personal stress. The authors conclude that the information available at this time is not sufficient for the development of a practical heat stress standard, and propose the use of physiological indicators of heat strain to evaluate the stress of a given job situation.
Thermal-effects; Heat-stress; Industrial-environment; Physiological-measurements; Body-temperature; Hot-environments
Proceedings of a NIOSH Workshop on Recommended Heat Stress Standards, September 17-19, 1979, Cincinnati, Ohio