Las Vegas logs another record-high but weeklong heat wave losing grip on Southwest

RENO, Nev. -- Records tumbled across the Southwest United States on Thursday as temperatures soared past 110 degrees Fahrenheit from southeast California to Arizona, where the region's first heat wave of the year was expected to maintain its grip for at least another day.

Although the official start of summer is still two weeks away, roughly half of Arizona and Nevada were under an excessive heat alert, which the National Weather Service said it was extending until Friday evening. The heat alert for Las Vegas was extended through Saturday.

"It's so hot," said Eleanor Wallace, 9, who was visiting Phoenix from northern Utah Thursday on a hike celebrating her birthday with her mother, Megan Wallace.

The National Weather Service in Phoenix, where the new record high of 113 F on Thursday leap-frogged the old mark of 111 F set in 2016, called the conditions "dangerously hot."

There were no immediate reports of any heat-related deaths or serious injuries.

But at a campaign rally for presumptive Republican presidential nominee Donald Trump in Phoenix, 11 people fell ill from heat exhaustion by late afternoon and were taken to the hospital, where they were treated and released, fire officials said.

And in Las Vegas, with a new record of 111 Thursday that also equaled the earliest time of year the high reached at least 110, the Clark County Fire Department said it had responded to at least 12 calls for heat exposure since midnight Wednesday. Nine of those calls resulted in a patient needing hospital treatment.

Several other areas of Arizona, California and Nevada also broke records by a degree or two, including Death Valley National Park with a record high for the date of 122 topping the 121 dating to 1996 in the desert that sits 194 feet below sea level near the California-Nevada line. Records there date to 1911.

The heat has arrived weeks earlier than usual even in places farther to the north at higher elevations - areas typically a dozen degrees cooler. That includes Reno, where the normal high of 81 F for this time of year soared to a record 98 F on Thursday. Records there date to 1888.

The National Weather Service forecast mild cooling regionwide this weekend, but only by a few degrees. In central and southern Arizona, that will still means triple-digit highs, even up to 110 F.

On Thursday in Phoenix, the unseasonably hot weather did not prevent Oscar Tomasio of Cleveland, Ohio, from proposing to his girlfriend, Megan McCracken, as they sweltered to the peak of a trail on Camelback Mountain with 3 liters of water each in tow.

"It was a grueling hike," Tomasio told The Associated Press. "It was extra hot, so we started extra early."

"The views were beautiful. We didn't make it quite to the top because she was a little nervous with the heat," he said. "So, I proposed to her when the sun rose."

McCracken confirmed they'd planned a sunrise hike and awoke about 5 a.m. in an effort to beat the heat and an impending closure of the trail.

"Probably not early enough," she said.

Megan Wallace, mother of the birthday girl from Utah who also came packing water bottles, said: "We started just a few minutes after 6 and it's like we came prepared, but we got through all of our water and it was hot - was hotter than we're used to."

Associated Press writers Anita Snow and Ty O'Neil in Phoenix, and Rio Yamat and Ken Ritter in Las Vegas contributed to this report.