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

Minimum Rest Time and Maximum Workload: Physical Aspects That Must Be Investigated to Enhance the IRSST’s Apps for Heat Stress in the Workplace


Between 1950 and 1959, Montreal experienced around 9 days a year with temperatures of 30°C and over. This number rose to 22 in 2020 and could reach 42 by 2050. According to data from the Commission des normes, de l’équité, de la santé et de la sécurité du travail (CNESST), total costs for injuries due to hot environments amounted to close to a billion dollars between 2012 and 2016. Every 1°C increase in the maximum daily temperature is associated with an increase in the risk of heat-related health problems, particularly heat stroke.

To minimize health problems related to heat in the workplace, the IRSST provides two web-based apps that calculate the alternating work/rest regimen based on the values users enter concerning environmental conditions (WBGT, Wet Bulb Globe Temperature), workload and the type of clothing worn by the worker.

This project is intended to improve these apps. The research team will determine the minimum rest time for a moderate workload executed in a hot environment. It will determine the optimal alternating regimen for a very high load in a hot environment and explore the effect of work/rest alternation on cognitive and physical fatigue when work is done in a hot environment. Another project objective is to characterize the effects of a hot day on construction workers’ psychophysiological responses.

Additional Information

Type: Project
Number: 2022-0011
Status: Ongoing
  • Daniel Gagnon (Institut de cardiologie de Montréal)
  • Philippe Gendron (Université du Québec à Trois-Rivières)
  • Capucine Ouellet (IRSST)
  • Alireza Saidi (IRSST)
  • Fabien Dal Maso (Université de Montréal)
  • Benjamin Pageaux (Université de Montréal)
  • Mickael Begon (Université de Montréal)
  • Ollie Jay (The University of Sydney)