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

Development of a WBGT utility


During very hot periods, workers who work outdoors can suffer discomfort, sometimes as severe as heat stroke. The Regulation respecting occupational health and safety (ROHS) prescribes Permissible Exposure Values (PEVs) for heat, based on the Wet Bulb and Globe Temperature (WBGT). The application of this measure however requires technical means that workplaces do not always possess. This is why the CSST has been proposing for several years the Guide de prévention des coups de chaleur (heat stroke prevention guide) which uses the parameter called the corrected air temperature procedure, which requires no specialized instruments. The researchers created a computer tool for calculating the corrected air temperature in relation to different variables. They also developed two others to establish an alternating work-rest regimen in relation to the provisions of Schedule V of the ROHS and the recent recommendations of the American Conference of Governmental Industrial Hygienists. These three computer tools for managing heat stress can be downloaded from the IRSST’s website.

Additional Information

Type: Project
Number: 0099-6650
Status: Completed
Year of completion: 2007
  • Daniel Drolet (IRSST)
  • Pierre C. Dessureault (Université du Québec à Trois-Rivières)
  • Laurent Gratton (IRSST)