‘Heat stress at work is no joke’
HR professionals should treat extreme heat as a workplace hazard demanding proactive planning, as rising emergency visits and employers' legal duties raise the stakes for those unprepared, according to one expert.
Global News reported that Toronto Public Health recorded 39 heat-related emergency visits between June 30 and July 4, 2026, during an orange-level heat alert from Environment and Climate Change Canada (ECCC). The highest single-day total, 15 visits, came July 2. Parts of Ontario, Quebec, the Northwest Territories and Newfoundland and Labrador remained under yellow heat warnings, the most common alert level, in the days after, ECCC said.
Erin Sailer, Board Chair of CPHR Canada, told HRD that the figures should concern HR leaders in every sector.
"A heat hangover might be something you joke about at work after a summer weekend, but heat stress at work is no joke. With more frequent and intense heat events, this isn't just an issue for outdoor workers. It can also affect warehouses, kitchens, manufacturing, healthcare settings, and even offices without adequate cooling," she said.
Legal duty to manage heat risk
Sailer said employers carry a legal duty to address heat exposure.
"Every employer in Canada has a legal duty to protect workers from foreseeable hazards. Several jurisdictions, including B.C., Manitoba and the territories, have specific heat stress exposure rules, while others rely on employers' general duty to take reasonable precautions to protect worker safety," she said.
For HR, the duty extends into business continuity planning, Sailer said.
The Canada Labour Code amendments, updated on Feb. 12, 2026, set out detailed expectations under Part X of the Canada Occupational Health and Safety Regulations (COHSR), including the use of ACGIH Threshold Limit Values (TLVs) for heat and cold, monitoring tools like humidex and wind chill, and specific requirements for training, reporting and controls under Part II of the Code.
Health and productivity risks mount
Sailer said heat directly drives workplace incidents. "The Canadian Centre for Occupational Health and Safety (CCOHS) talks about how heat can affect concentration, reaction time, moods, and decision-making. Workers can become fatigued, dehydrated or dizzy, increasing the risk of mistakes, vehicle incidents or other workplace injuries. In more serious cases, heat can lead to heat exhaustion or heat stroke, which is a medical emergency," she said.
CCOHS noted that heat can also affect concentration, memory and mood.
"For employers, heat events can mean higher absenteeism, lower productivity, more workplace incidents, and operational disruptions. It can also expose organizations to regulatory scrutiny if appropriate precautions are not taken," she said.
Sailer said this is why HR should manage heat like any occupational hazard.
Employers must act before temperatures climb
Sailer said preparation must start well before extreme heat arrives. "The best time to prepare for extreme heat is before the forecast hits 35 degrees, not after someone gets sick," she said.
She recommended starting with risk assessment. "Start by assessing the actual heat risk. It's not just the air temperature that matters. Humidity, radiant heat, physical workload, air movement, clothing, and PPE all affect how much heat workers experience," she said.
From there, employers should turn to practical controls and training, Sailer said.
"Whenever possible, reduce the heat exposure itself through ventilation, air conditioning, shade, whatever can work for the space. If that's not possible, adjust the work by scheduling the most physically demanding tasks during cooler parts of the day, rotate workers, and change-up the work/rest cycle. Train supervisors and workers to recognize the early signs of heat stress, and have a clear emergency response plan," she said.
In May, the federal government warned of record-breaking heat ahead of the summer, and that British Columbia faces the "highest and most sustained" wildfire danger of the 2026 season.
A majority of the world's workforce are exposed to health hazards exacerbated by climate change, according to a report released by the International Labour Organisation (ILO) in 2024.
