OS ANGELES, June 21 — A scorching Lheatwave in the western United States has grounded flights, caused fires and prompted power outages, with record temperatures expected yesterday in several states including Arizona and Nevada.

The extreme temperatures prompted American Airlines on Tuesday to ground 43 flights to and from Phoenix Sky Harbour Airport, where temperatures were set to reach a record 120 degrees Fahrenheit (49 degrees Celsius).

Company spokesman Ross Feinstein told AFP the flights were run by two regional partners — Skywest and Mesa — which operate smaller airplanes that cannot take off when temperatures reach a certain level.

"Each aircraft has different International Standard Atmosphere (ISA) performance specifications, which is set by the aircraft manufacturer,” Feinstein said. "This also takes into account the elevation at the airport.

"For Phoenix, that is limited to 118 degrees.”

He said the airline’s other mainline flights, which concern larger jets, had not been affected by the blazing temperatures.

The soaring heat has affected much of the western United States where triple-digit temperatures were expected throughout the week in several states including Nevada and California, a spokeswoman for the National Weather Service said.

"Yesterday in Phoenix we tied the record for last year, which was 116 degrees, and now we are expecting to hit 120 degrees today,” Bianca Hernandez told AFP.

She added that temperatures were expected to stay in the 110-115 range until next week.

In California, the National Weather Service issued an excessive heat warning for southern parts of the state including the cities of Banning and Desert Hot Springs, where temperatures could soar as high as 122 degrees.

Officials said the heat has led to electricity outages, as more people turn on air conditioners, overtaxing the power system.

Several wildfires were also burning in the state, including a massive one in the San Bernardino National Forest, east of Los Angeles, where 450 firefighters were battling the blaze that has already scorched 950 acres.

Authorities urged people to stay indoors and keep hydrated to avoid any heat-related illnesses.

"If you can avoid being outside in general, that’s the best thing you could do today,” Fernandez said. "Everyone should hydrate, and if you have to be outside, try to do so before the sun rises or after sunset.” — AFP