Heat Waves Put Extra Strain on Canada’s Power Grids
Why Heat Increases Demand
When temperatures stay high for multiple days, people run air conditioners and fans nonstop, raising electricity use dramatically.
Expert Warning About Cascading Failures
Jeff Siegel, a civil engineering professor at the University of Toronto, explains that if one section of the grid trips offline, the remaining lines carry more load, which can overload them and trigger further outages—a cascade effect.
Historical Context
Past incidents show that outages can spread across the entire national grid when heat and other stressors combine.
Recent Weather‑Related Outages
On July 2, severe thunderstorms that followed a heat wave knocked out power to thousands of residents in parts of Ontario and Quebec, illustrating how heat and storms together heighten grid vulnerability.
Other Stressors Besides Heat
Thunderstorms occurring during heat waves can spark wildfires and add additional strain on the system, according to Siegel.
Maintaining Air Conditioning to Avoid Failures
Annual Service Is Recommended
Air conditioning units should be inspected and serviced at least once a year, preferably in the spring, to ensure they operate reliably during extreme heat.
Key Maintenance Steps
Changing or cleaning the filter, checking refrigerant levels, and confirming that outdoor components are free of debris help the system handle higher demand.
How Canadians Can Stay Cool During Heat Waves
Practical Cooling Strategies
Opening windows at night and using fans to draw in cooler air, reducing physical activity, and staying hydrated are effective ways to lower body temperature.
Using Moisture to Enhance Evaporation
Soaking clothing in cold water or draping a wet towel on the skin mimics sweating and provides a quick cooling effect without increasing indoor humidity.
Indoor Air Quality Tips
Keeping windows closed and blinds drawn during the hottest part of the day, then ventilating in the evening, helps keep indoor temperatures down while maintaining clean air.
Health Risks and Vulnerable Groups
Who Is Most at Risk
Health Canada notes that people over 65, infants and young children, individuals with chronic respiratory or heart conditions, and those who work or exercise in the heat face the greatest health risks from heat stress.
Preparing for Power Outages
Creating an emergency kit with food, water, and a battery‑operated or wind‑up flashlight, and developing a household plan for heat events, can protect vulnerable members if electricity is lost.
