Wildfires are raging in the west of the United States as the region is hit by a heatwave that has brought record temperatures to several areas.
Communities have been told to evacuate as firefighters struggle to battle the blazes in the extreme conditions.
Two firefighters in Arizona died when their aircraft crashed while responding to a wildfire.
Meanwhile, Las Vegas matched its all-time temperature high of 47.2C (117F) on Saturday.
It comes just weeks after another dangerous heatwave hit North America, in which hundreds of sudden deaths were recorded, many of them suspected of being heat-related.
The region experienced its hottest June on record, according to the EU's Earth observation programme.
Experts say that climate change is expected to increase the frequency of extreme weather events, such as heatwaves. But linking any single event to global warming is complicated.
However, a study by climate researchers said the heat that scorched western Canada and the US at the end of June was "virtually impossible" without climate change.
Firefighters battling the many wildfires in the region say the air is so dry that much of the water dropped by aircraft to quell the flames evaporates before it reaches the ground.
Arizona's Bureau of Land Management paid tribute to the two "brave wildland firefighters" who died in a plane crash while performing aerial reconnaissance, command and control over the lightning-caused Cedar Basin Fire.
"Our hearts are heavy tonight with sincere condolences to families, loved ones and firefighters affected by this tragic aviation accident", the agency said.
The accident occurred at around noon local time (19:00 GMT) on Saturday near the small community of Wikieup. Further information was not immediately available and the firefighters have not been officially named.
In the north of Nevada, near the border with California, people were evacuated from their homes as wildfires triggered by lightning strikes tore through parts of the Sierra Nevada forest region.
One fire, which more than doubled in size between Friday and Saturday, sent up a giant cloud of smoke and ash which, combined with the dry heat, generated its own lightning, according to the Los Angeles Times.