Heat stress

Extreme heat has been breaking records across Europe, Asia and North America, with millions of people sweltering in heat and humidity well above “normal” for days on end. Death Valley hit a temperature of 128 degrees Fahrenheit (53.3 degrees Celsius) on July 16, 2023 – not quite the world’s hottest day on record, but close. Phoenix broke a record heat streak with 19 straight days with temperatures above 110 F (43.3 C), and had more in the forecast, accompanied by several nights that never got below 90 F (32.2 C). Globally, Earth likely had its hottest week on modern record in early July. Heat waves are becoming supercharged as the climate changes – lasting longer, becoming more frequent and getting just plain hotter. One question a lot of people are asking is: “When will it get too hot for normal daily activity as we know it, even for young, healthy adults?” The answer goes beyond the temperature you see on the thermometer. It’s...

The heat dome that descended upon the Pacific Northwest in late June 2021 met a population radically unprepared for it. Almost two-thirds of households earning US$50,000 or less and 70% of rented houses in Washington’s King, Pierce and Snohomish counties had no air conditioning. In Spokane, nearly one-quarter of survey respondents didn’t have in-home air conditioning, and among those who did, 1 in 5 faced significant, often financial, barriers to using it. Imagine having no way to cool your home as temperatures spiked to 108 degrees Fahrenheit (43 Celsius), and 120 F (49 C) in some places. People in urban heat islands – areas with few trees and lots of asphalt and concrete that can absorb and radiate heat – saw temperatures as much as 14 F (7.8 C) higher than that. Extreme heat disasters like this are becoming increasingly common in regions where high heat used to be rare. Blackouts during severe heat waves can also leave residents who believe they are...