In 2021 extreme heat killed more Americans than any other weather-related disaster. People seek shelter after tornado warnings, and leave coastal areas before a hurricane hits. Yet many ignore extreme-heat advice.
In July over 150m Americans, or nearly one in two, were in parts of the country issuing such alerts.
In the Great Plains heat indices (a measure of how heat is felt by the body) rose to 49°C. In the run-up to Labour Day, which this year falls on September 5th, over 50m were in areas on alert as a sustained heatwave was forecast in western states. Officials have urged Californians to cut their energy use to help the state avoid rolling blackouts.
America’s cities are struggling to deal with heat. Last year the first “chief heat officer” was appointed in Miami-Dade County; Los Angeles and Phoenix followed suit. Their job is to raise public awareness of the dangers of high temperatures.
People get used to routine risks, explains Erick Bandala, a scientist at the Desert Research Institute (dri) in Las Vegas. Mr Bandala likens attitudes to heat to the ease with which many people drive a car. Heat, because it feels familiar, can be a surprise killer.