PHOENIX, Ariz. (CBS/AP) -- A blazing heat wave expected to send the mercury soaring to nearly 120 degrees in Phoenix and Las Vegas settled over the West on Friday, threatening to ground airliners and raising fears that people and pets will get burned on the scalding pavement.
Meteorologist Jeff Berardelli of CBS station WFOR-TV told "CBS This Morning" that the extreme heat "is going to be about as extreme as it gets. In fact, almost a once-in-a-century-type heat wave in the deep Southwest."
The National Weather Service warned that exceedingly hot temperatures are expected through Monday, with little relief expected at night, and that the heat wave has the potential to be a life-threatening heat event for those at risk.
The heat was so punishing that rangers took up positions at trailheads at Lake Mead in Nevada to persuade people not to hike. Zookeepers in Phoenix doused elephants with water and fed tigers frozen fish snacks. And tourists at California's Death Valley took photos of the harsh landscape and a thermometer that read 121.
The mercury there was expected to reach nearly 130 on Friday — just short of the 134-degree reading from a century ago that stands as the highest temperature ever recorded on Earth.
"You have to take a picture of something like this, otherwise no one will believe you," said Laura McAlpine, visiting Death Valley from Scotland.
CBS News correspondent Bill Whitaker reported that California is expecting demand for electricity to heat up. Steve Berberich oversees the state's power grid. "Turn up your air conditioner just a couple of degrees," he advised. "It may be a little bit uncomfortable, but it's a lot more uncomfortable if you don't have enough power."
The heat presented problems for airlines because extreme temperatures make it difficult for smaller planes to lift off. When the air gets so hot, it becomes less dense, requiring longer runways and less fuel in the tanks to reduce weight.
Officials said big jetliners function fine in the heat, but smaller regional airlines may have delays.
The National Weather Service said Phoenix could reach 118 on Friday, while Las Vegas could see the same temperature over the weekend in what would be a record for Sin City. The record in Phoenix is 122.
With Las Vegas hot, air conditioning repairman Michael Gamst is working overtime, Whitaker reported."Very busy," said Gamst. "We started extremely early and I don't know what time we're gonna get done."