Heat Stress, Work Function and Physiological Heat Exposure Limits in Man.

摘要

Various operational trials using tolerance criteria available in the literature revealed that predictions of physiological exposure limits were rarely compatible with the observed status of men in a wide range of heat stress and work conditions. Computer integration of laboratory and industrial-type data led to establishing a comprehensive set of physiological criteria for tolerance limits appropriate to man at work within time-weighted-mean (twm) metabolic rates. These criteria and work rates were integrated with industrial-type heat stress conditions which resulted in developing the Physiological Heat Exposure Limits (PHEL) concept. Several electronic heat stress monitor-devices were evaluated and employed in determining environmental conditions. Comparison of over 200 sets of environmental and physiological data supported the PHEL concept and permitted more definitive identification of material areas requiring corrective engineering actions in the industrial-type settings. Corrective engineering actions based upon results of the data analyses have permitted nearly a sixfold increase of the maximum physiological exposure times; simultaneously, the estimated cardiovascular reserve increased from 15% to as much as 85% during routine work.