Workers try to stay hydrated in Toronto as the city grapples with a heat wave on June 23, 2025.Sammy Kogan/The Globe and Mail
Scorching heat waves are becoming a regular feature of Canadian summers, yet not enough attention is being paid to some of the people most at risk of heat-related health problems – outdoor workers. A new legislative push is needed to modernize provincial workplace rules to account for rising temperatures as well as poor air quality due to wild fire smoke.
Farm labourers, construction workers, landscapers and other outdoor employees face a high risk from heat. Some indoor workers are also at risk from high temperatures in the summer or year round, particularly those in industrial kitchens and certain manufacturing plants.
A 2025 report from the World Health Organization on heat stress, a condition when the body accumulates heat, leading to physiological strain, says the frequency and intensity of extreme heat events has risen sharply due to climate change, boosting risk for outdoor and indoor workers around the world. Health risks include heat stroke, dehydration, kidney dysfunction, and neurological disorders. Heat also decreases worker productivity and can lead to cognitive impairment, resulting in accidents.
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Between 2021 and 2025, WorkSafeBC accepted 335 heat-related injury claims, many in transportation, construction, food services, and film and television production. While workplace deaths in Canada due to heat are rare, it can be a contributing factor in fatalities attributed to heart attacks and respiratory disease.
A new report from BC Policy Solutions says that existing heat exposure regulations in the province lack clarity, aren’t widely known by workers, and are poorly enforced. It recommends adapting a “trigger temperature” for when heat-related requirements come into effect, making it clearer to workers and employers what actions are required.
Ontario’s Occupational Health and Safety Act doesn’t include specific obligations around heat stress or maximum workplace temperature limits, although employers have a general duty to take “reasonable” measures to protect workers. In 2023, the Ministry of Labour said it would create specific requirements for employers regarding heat, but the proposal stalled after employer groups complained the rules would be expensive and complicated, and labour advocates said vulnerable groups, such as farm workers, were left out.
Abandoning the effort isn’t the answer. Clear and simple rules can be created that boost worker protections without bogging down employers in needless regulations and red tape.
A private member’s bill introduced by NDP MPP Peter Tabuns offers some sensible ideas, such as mandating paid cool-down breaks, requiring employers develop and implement heat stress policies, and providing access to cool drinking water. New rules from Ottawa covering federal workers are also a good model. Other provinces should enact similar legislation, while adding provisions for employees exposed to wildfire smoke.
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These rules should clearly cover temporary agency workers and migrant farm workers, who are among those most exposed to heat and smoke, says Godfred Boateng, associate professor at York University’s School of Global Health. Labour ministries shouldn’t rely entirely on complaints from workers – many who have temporary status and may be scared to speak up – to ensure employers are meeting their obligations. Unannounced site visits are needed.
Updated regulations will provide employers clarity, but they shouldn’t wait to improve their strategies. Employers should provide training so supervisors can recognize symptoms of heat stress and react properly. Supervisors should understand that workers may react differently to the same conditions; given that commonly used thresholds to measure heat stress were developed for young, male army recruits, adjustments may be needed for women and older workers.
Supervisors need to be proactive and monitor weather forecasts, but they also must adapt as circumstances change. Worker safety and productivity can be boosted by shifting heavier work to the mornings, with lighter duties in the afternoon, says Glen Kenny, a professor of physiology at the University of Ottawa. Rotating staff between hotter and cooler environments can also prevent worker fatigue.
Provincial leaders should make modernizing heat regulations for workers a priority. By next summer, there will be no excuse not to have new rules in place.