What could be the highest temperature ever reliably recorded on Earth - 130F (54.4C) - may have been reached in Death Valley National Park, California.
The recording is being verified by the US National Weather Service.
It comes amid a heatwave on the US's west coast, where temperatures are forecast to rise further this week.
The scorching conditions have led to two days of blackouts in California, after a power plant malfunctioned recently. What were the previous records?
Before this, the highest temperature reliably recorded on Earth was 129.2F (54C) - also in Death Valley in 2013.
A higher reading of 134F, or 56.6C a century earlier, also in Death Valley, is disputed. It is believed by some modern weather experts to have been erroneous, along with several other searing temperatures recorded that summer.
According to a 2016 analysis from weather historian Christopher Burt, other temperatures in the region recorded in 1913 do not corroborate the Death Valley reading.
Another record temperature for the planet - 131F, or 55C - was recorded in Tunisia in 1931, but Mr Burt said this reading, as well as others recorded in Africa during the colonial era, had "serious credibility issues".
