The US southwest is bracing for record temperatures, with Death Valley inching closer to the all-time recorded high of 134.

The death of a man in Las Vegas was attributed to the 115-degree heat there late Saturday, while Phoenix hit 119 degrees, breaking the record for June 29 set in 1994, and large swaths of California sweltering, the Associated Press reported.

Death Valley in California recorded 127 degrees, according to unofficial reports cited by CNN. (The 134 degrees there a century ago was the highest temperature ever recorded on Earth.)

Highs between 115 and 120 degrees were expected for parts of Arizona, Nevada, and California through the weekend and possibly lasting until Tuesday, according to the National Weather Service.

They described the heat as potentially life-threatening.

National Weather Service specialist Stuart Seto told the AP that the heat wave is "a huge one."

"We haven't seen one like this for several years, probably the mid- to late 2000s."

The death of a man in his 80s in Las Vegas was heat-related, according to reports.

CNN, citing a Las Vegas Fire & Rescue spokesman, wrote that paramedics found the man dead in his home, which did not have air-conditioning.

He died of cardiac arrest.

Meanwhile, CNN reported that air-conditioning salespeople were working overtime.

Max Ghaly of Cathedral City Air Conditioning and Heating in Palm Springs, California: