'Adapting public buildings to the heat means protecting both the people who use them and those who work there'
Quebec advocacy groups are pushing the province to rewrite its Building Code and workplace heat rules after a new survey found widespread health effects among workers exposed to extreme heat, according to a report.
The Quebec Coalition for a Right to Coolness wants a "responsible cooling strategy" covering ventilation, shade and rest breaks.
Adapting public buildings was identified as the top priority among Quebecers surveyed in a new Léger poll conducted for the Quebec Public Health Association (ASPQ), with 68 per cent of workers favouring cooling upgrades to schools, hospitals, senior residences and libraries.
"Adapting public buildings to the heat means protecting both the people who use them and those who work there," said Cyril Frazao, director of health and climate at the ASPQ, calling for prevention to be built into building renovation and design.
The ASPQ and the Quebec Federation of Labour (FTQ), both members of the Quebec Coalition for a Right to Coolness, are asking political parties to strengthen worker protections, including through CNESST field interventions, adopt a cooling strategy for public buildings, and invest in resilient environments for the most vulnerable populations. "The data is clear: we must better protect workers and adapt our buildings to the extreme heat," Frazao said.
Effects of extreme heat
The poll found that 72 per cent of employed Quebecers experienced at least one effect of extreme heat in the past three years.
The most frequently cited effects were:
- increased fatigue or difficulty concentrating (39 per cent)
- thirst or dehydration symptoms (36 per cent)
- reduced motivation at work (32 per cent).
Beyond health effects, 22 per cent of respondents said their work became harder to complete, or suffered in quality, during periods of intense heat.
Calls for government action
The poll found 54 per cent of the general population believes the Quebec government should do more to protect workers in heat-exposed sectors such as agriculture, construction and events. That figure rose to 62 per cent among women and renters.
"When nearly three out of four employed people tell us that the heat is already affecting their daily work life, we are no longer talking about a future problem," said Patrick Rondeau, director of the Environment and Just Transition Department at the FTQ.
Rondeau added that exposure extends beyond outdoor trades. "It also affects people who spend their days in schools, health facilities, senior residences, or other buildings that are likely to overheat. Prevention must cover all workplaces," he said.
Here's a summary of the major occupational dangers linked to extreme heat exposure, based on research from Canadian and international occupational health authorities.
|
# |
Danger |
Description |
Source |
|
1 |
Heat exhaustion and heat stroke |
The Canadian Centre for Occupational Health and Safety notes that heat stress causes a spectrum of disorders ranging from heat rash and cramps to life-threatening heat exhaustion and heat stroke. Heat stroke, the most severe form, can cause irreversible damage to the heart, lungs, kidneys and liver if not treated immediately. |
Canadian Centre for Occupational Health and Safety (via IHSA), "Heat Stress"; Sun Safety at Work Canada study, BMC |
|
2 |
Acute and chronic kidney injury |
A 2025 review in the Journal of Climate Change and Health found that outdoor workers face significant risk of acute kidney injury and chronic interstitial nephritis from repeated heat exposure and dehydration, estimating roughly 4.8 million U.S. outdoor workers experience heat-related kidney strain. A separate Thai cohort study found men with prolonged occupational heat exposure were 2.22 times more likely to develop kidney disease than unexposed workers. |
Werner, Carrion & Huguet, "Risk for renal injury from heat-related stress among outdoor workers," Journal of Climate Change and Health, 2025; Science.gov summary of occupational heat stress and kidney disease cohort study |
|
3 |
Cardiovascular strain and cardiac events |
Research led by Dr. Daniel Gagnon found that even a 0.5°C rise in core body temperature triggered myocardial ischemia in over a third of older adults with coronary artery disease during passive heat exposure, despite no symptoms of angina. Heat exposure increases cardiac output and workload as the body redirects blood flow to the skin to cool down, placing added strain on the heart. |
Gagnon, "Exposure to heat has significant effects on the heart," Observatoire de prévention, July 17, 2024 |
|
4 |
Cognitive impairment and elevated accident risk |
The American Industrial Hygiene Association reports that heat can reduce the brain function responsible for reasoning, while sweaty palms, fogged safety glasses and dizziness create additional safety hazards on the job. A 2025 comment package submitted to OSHA by the American College of Occupational and Environmental Medicine cited research showing occupational injury rates rose by nearly 10 per cent with increases in workplace temperature. |
"Heat Hazards," The Synergist, AIHA; ACOEM Comment Package, Occupational Heat Standard, submitted to OSHA, Jan. 13, 2025 |
|
5 |
Rhabdomyolysis and heat-related burns |
Rhabdomyolysis, the breakdown of injured muscle tissue that releases proteins and electrolytes into the bloodstream, can be triggered by excessive heat and may cause serious harm to the kidneys and heart. Workers also face burn risks from contact with hot surfaces, steam or equipment, an additional hazard flagged separately by NIOSH-based safety guidance. |
"Working in Heat: A Summary of CCOHS, Albertan, and OSHA Recommendations"; Maryland Occupational Safety and Health (MOSH), "Heat Stress" |
