Heat Stress at Work in Canada: Employer Safety Checklist for Summer 2026

Last reviewed: June 2026  |  Jurisdiction: Canada (all provinces and territories, plus federal)  |  Applies to: Canadian employers in hospitality, construction, warehousing, landscaping, delivery, retail, manufacturing, agriculture, healthcare, and office settings. Heat stress is no longer just an outdoor construction issue. In Canada, employers now need to think about heat risk in restaurants, kitchens, warehouses, delivery work, farms, landscaping, manufacturing, retail spaces, healthcare settings, and offices where cooling is poor or unreliable. Summer heat can affect workers quickly. A worker may start a shift feeling normal, but as the day gets hotter, the body may struggle to cool itself. This can lead to fatigue, dizziness, muscle cramps, poor concentration, nausea, fainting, heat exhaustion, or heat stroke. For employers, heat stress is both a health and safety issue and a business risk. The good news is that most heat-related workplace incidents can be reduced with practical planning. This guide explains what Canadian employers should know for summer 2026 and provides a sample heat stress policy template that can be adapted for many workplaces. This article provides general workplace safety information for Canadian employers. It is not legal advice. Employers should confirm the specific occupational health and safety requirements that apply in their province, territory, sector, and workplace. What Is Heat Stress at Work? Why Heat Stress Matters in Summer 2026 Which Workplaces Are Most at Risk? Employer Duties: What Canadian Employers Should Understand Federal Thermal Stress Update: Important 2027 Compliance Note Indoor Heat Stress vs Outdoor Heat Stress Heat Stress Risk Factors Employers Should Assess Warning Signs Managers and Supervisors Should Know What to Do When a Worker Shows Heat Stress Symptoms How to Prevent Heat Stress at Work What a Heat Stress Policy Should Include Sample Heat Stress Policy Template Training Checklist for Workers and Supervisors Daily Supervisor Heat Stress Checklist Industry-Specific Examples Common Mistakes Employers Should Avoid Practical Summer 2026 Action Plan Frequently Asked Questions Suggested Official Sources Heat stress happens when the body gains more heat than it can safely release. The body normally cools itself by sweating and increasing blood flow to the skin. But in a hot workplace — especially when the air is humid, the work is physically demanding, or the worker is wearing heavy protective clothing — sweating may not be enough. Environmental heat This includes hot weather, direct sunlight, humidity, radiant heat from pavement or roofs, poor ventilation, ovens, boilers, dryers, industrial equipment, kitchens, and hot vehicles. Work-related heat The harder the body works, the more heat it produces. Lifting, carrying, digging, cleaning, loading, moving quickly, climbing stairs, working on roofs, or performing repetitive physical tasks can increase the worker's internal heat load. Worker-specific factors Some workers may be more vulnerable because they are new to the job, not used to working in heat, returning after time away, dehydrated, tired, wearing heavy clothing or PPE, taking certain medications, or dealing with a health condition that affects heat tolerance. Temperature alone does not tell the full story. A workplace can become risky at lower temperatures if humidity is high, air movement is poor, the job is physically demanding, or the worker is wearing protective clothing that traps heat. Heat stress should be a priority for employers in summer 2026 for four main reasons. 1. Heat is a foreseeable workplace hazard For many workplaces, summer heat is not a surprise. It is seasonal, predictable, and manageable with proper planning. If employees work outdoors, near hot equipment, in poorly ventilated spaces, in vehicles, in kitchens, in warehouses, or while wearing heavy PPE, heat stress should be part of the workplace hazard assessment. 2. Heat affects safety, not only comfort Heat stress is not just about discomfort. It can reduce attention, slow reaction time, increase fatigue, affect judgment, and raise the risk of other workplace incidents. A hot worker may be more likely to make mistakes while driving, using equipment, climbing ladders, handling tools, moving materials, or working near co-workers. 3. Indoor heat stress is often missed Many employers think heat stress is only an outdoor issue. That is not correct. Indoor workplaces can become hazardous when heat builds up or ventilation is poor. Restaurant kitchens, bakeries, laundries, factories, warehouses, mechanical rooms, retail stores, and offices without reliable cooling can all create heat stress risk. 4. Federal rules are changing for 2027 In January 2026, the federal government finalized new thermal stress requirements for federally regulated workplaces. These requirements are not yet in force for summer 2026 . They are set to take effect on January 30, 2027. This g