NIOSHTIC-2 Publications Search

Review, Summarization, And Evaluation Of Literature To Support The Update And Revision Of Criteria Documents. XIII. Hot Environments.

NIOSH 1973 Mar:47 pages
An occupational hazard assessment of hot environments is reviewed and evaluated. Its purpose is to provide an update for the existing NIOSH criteria document. New information on human and animal toxicity, exposure, work practices, engineering controls, and biological and medical surveillance is included. The standard for heat stress considers both climatic and work load conditions on workers. These measurements must account for individual physiological responses to different stress. Heart rate and rectal temperature are measures used to set the standard. Heat exposure has not proven to be stressful on a short term basis even over a number of years. An index based on local and total body sweating rates would provide a better indication of strain than heart rate and temperature. Elevation of deep body temperature to above 38 degrees-C seems to be necessary for acclimatization, but the degree of exercise has no influence on improvements. Acclimatization to dry heat is better accomplished by light work in a hot, dry environment rather than a hot, humid one with equal stress. One factor which can be readily altered in the control of thermal balance is the work load. The authors conclude that further research examining the actual physiological responses of workers under different environmental conditions at the job site is necessary in order to validate any suggested toxic limit values.
NIOSH-Contract; Heat-exposure; Safety-research; Safety-measures; Employee-exposure; Occupational-exposure; Industrial-exposures; Medical-monitoring; Contract-210-76-0167;
Publication Date
Funding Type
Fiscal Year
Identifying No.
Source Name
NIOSH, U.S. Department of Health, Education and Welfare, Rockville, Maryland
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division