IRSST - Institut de recherche Robert-Sauvé en santé et en sécurité du travail

Data collection and verification of the agreement between the corrected air temperature and the WBGT index in outdoor thermal environments


A few years ago, the CSST produced a heat stroke prevention guide based on the corrected air temperature. This guide allows workers’ level of exposure to hot environments to be estimated and proposes means for risk reduction. The authors of this report verified the correspondence between the method for corrected air temperature proposed in the Guide and the WBGT (Wet Bulb Globe Temperature) traditionally used in workplaces. It was found that when the air temperature is read in the workplace, use of the corrected air temperature obtained after application of correction factors for humidity and sunshine is very prudent, and often even overestimates the level of thermal stress expressed by the WBGT measured in the same location. However, hard work under cloudy conditions is an exception, with a 23% underestimation of the exposure. The authors believe that use of the Guide from meteorological sources should therefore be limited to light and medium work, and they make recommendations to improve and simplify the process proposed in the Guide.

Additional Information

Type: Project
Number: 0099-4270
Status: Completed
Year of completion: 2006
Research Field: Special Projects
  • Pierre C. Dessureault (Université du Québec à Trois-Rivières)