More than 200 people have deceased in Canada since Friday as temperatures hit a record high of 49.1°C in the past four days.
In Vancouver, residents were seen fleeing homes without air conditioning flocked to downtown hotels, queuing for hours in long lines to check in. Air conditioners sold out in stores and online. Peak power demand shattered the prior record by more than 600 megawatts, roughly equivalent to the capacity of some coal power plants.
At least 233 people died in the West coast province of British Columbia between Friday and Monday, about 100 more than the average for a four-day period. They added that the number was expected to rise as more reports were filed.
Environment Canada has issued alerts for British Columbia, Alberta, and parts of Saskatchewan, Manitoba, Yukon and the Northwest Territories, saying the "prolonged, dangerous and historic heat wave will persist through this week."
On Tuesday the temperature reaching 49.5 degrees Celsius in Lytton, British Columbia. The heat wave has forced schools and Covid-19 vaccination centres to close in the Vancouver area.
Temperatures in the US Pacific Northwest cities of Portland, Oregon and Seattle, Washington reached levels to 46.1 degrees Celsius in Portland and 42.2°C in Seattle on Monday.
The US National Weather Service has issued a warning, urging people to "stay in air-conditioned buildings, avoid strenuous outdoor activities, drink plenty of water, and check on family members/neighbours."
Heat exposure can lead to severe or fatal results, particularly in older people, infants and young children and those with chronic illnesses.
Heat waves begin when high pressure in the atmosphere moves in and pushes warm air toward the ground. That air warms up further as it is compressed, and we begin to feel a lot hotter.
As the ground warms, it loses moisture, which makes it easier to heat even more. As that trapped heat continues to warm, the system acts like a lid on a pot called “heat dome.”