- 23 updates
More than 40 people have been hospitalised in Las Vegas since Friday, as a heatwave blistered parts of the US.
Las Vegas fire and rescue spokesman Tim Szymanski said: "We will probably start to see a rise in calls Sunday and Monday as the event prolongs.
"People's bodies will be more agitated the longer the event lasts and people may require medical assistance".
A man died and another was in hospital is a serious condition as a heatwave has blistered parts of the US.
Forecasters said temperatures in Las Vegas shot up to 46 C (11 F) yesterday, two degrees short of the city's all-time record.
Phoenix hit 48.3C (119F) by mid-afternoon, breaking the record for June 29 that was set in 1994. And large areas of California sweltered under extreme heat warnings, which are expected to last into Tuesday night.
Dozens of people have been treated for heat-related ailments across the western United States, as the region sweltered on Saturday in dangerous triple-digit temperatures.
At least one heat-related death was reported by authorities in Las Vegas, where a man in his 80s was found dead inside a house that had no air-conditioning.
The victim suffered from other medical issues, but paramedics suspect heat was a contributing factor in his death, said Las Vegas Fire and Rescue spokesman Tim Szymanski.