Weather advisories are in place from the east to the west coast, with people told to drink plenty of water, stay out of the sun, seek air-conditioned shelter and to never leave children or pets unattended in vehicles.
An extreme heatwave in the US has seen record-breaking temperatures with warnings issued to around 130 million people and heightened concerns over wildfires.
San Francisco saw the thermometer hit a blistering 47C (117F) over the weekend while Las Vegas topped out at 46C – a high last reached in 2007.
Phoenix recorded 45.5C, just shy of the record of 46.7C set back in 1942.
The National Weather Service said it was extending the excessive heat warning for much of the southwest.
The agency in Las Vegas said: “A dangerous and historic heatwave is just getting started across the area, with temperatures expected to peak during the Sunday-Wednesday timeframe.”
Even in more temperate parts of the country – the Pacific Northwest, the mid-Atlantic and the northeast – temperatures were forecast to spike above 38C (100F).
More extreme highs are also expected.
Temperatures are set to reach 53.8C (129F) on Sunday at the aptly named Furnace Creek, in Death Valley National Park, California, rising to 54.4C by Wednesday.
The hottest temperature ever officially recorded on Earth was 56.67C (134F) in July 1913 in Death Valley, although some experts dispute that measurement and say the real record was 54.4C, reached there in July 2021.
The eastern US is also bracing for more hot temperatures.
Baltimore and others parts of Maryland were under an excessive heat warning as temperatures were forecast to climb to 43C (110F).
Crews tackle fire amid heatwave
A National Weather Service advisory for the Baltimore area said: “Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbours.
“Young children and pets should never be left unattended in vehicles under any circumstances.”
Sweltering temperatures have also led to deaths.
In Arizona’s Maricopa County, which includes Phoenix, there have been at least 13 confirmed heat-related fatalities this year, with a further 160 being investigated.
This figure does not include the death of a 10-year-old boy last week in Phoenix who suffered a “heat-related medical event” while hiking with his family.
Wildfires in California have also been fanned by the dry conditions and high temperatures.
Firefighters have used aircraft and helicopters to drop water and retardant in a bid to tackle blazes.
In Santa Barbara County, northwest of Los Angeles, a fire has scorched an area of more than 19sq miles (49sq km).
Crews said the blaze was displaying “extreme fire behaviour” and had the “potential for large growth” due to the weather conditions.
Emily Foster is a globe-trotting journalist based in the UK. Her articles offer readers a global perspective on international events, exploring complex geopolitical issues and providing a nuanced view of the world’s most pressing challenges.
