Parts of the US are expected to see record temperatures today, with warnings of “dangerous” heat levels into next week across the southwest.
Nearly a third of Americans – about 113 million people – are currently under heat advisories, from Florida to California and up to Washington state.
The country’s National Weather Service (NWS) has urged people not to underestimate the risk to life.
On Saturday, an all-time high of 48 degrees Celsius was recorded in Phoenix, Arizona.
It means temperatures have hit 43 degrees Celsius for 16 days running, itself almost a record.
Mobile clinics there have reported treating homeless people suffering from third-degree burns.
Meanwhile, Death Valley in California – one of the hottest places in the world – is forecast to reach 54C, nearing the hottest temperatures ever reliably recorded on Earth.
The NWS has said that local records could also be set today in the San Joaquin Valley, Mojave Desert, and Great Basin regions.
Its Saturday-evening update said the temperatures would “pose a health risk and are potentially deadly to anyone without effective cooling or adequate hydration”.
About 700 people are estimated to die each year from heat-related causes in the US, according to the Centers for Disease Control and Prevention (CDC).
In neighboring Canada, officials say wildfires stoked by above-average temperatures – which have covered parts of the US in smoke – have now burned nearly 25 million acres of land.
