Swaths of California sweltered Tuesday and things were only expected to get worse during the Fourth of July holiday week for parts of the United States with nearly 90 million people under heat alerts.
The torrid conditions were being caused by a ridge of high pressure just off the West Coast and a separate ridge that spawned heat warnings and advisories from Kansas and Missouri to the Gulf Coast states, according to the National Weather Service.
California's capital, Sacramento, was under an excessive heat warning expected to last until Sunday night, with temperatures forecasted to reach between 40.5-46 Celsius (105-115 Farenheit).
John Mendoza, 35, called it a "firehose of heat" as he walked around the Capitol on Tuesday morning with an iced coffee in his hand. By 9 a.m., he had already been in a pool once — and planned to go back later in the day.
"I felt like I needed to be submerged in water," he said.
Darlene Crumedy of Fairfield, about an hour's drive from Sacramento, said she doesn't use air conditioning because it's too expensive.
"I'm good, I have a hundred fans," she said, adding she tries to stay inside and drink cold water.
An analysis by The Associated Press found that heat killed more than 2,300 people in the U.S. last year, setting a record. That figure is likely a major undercount, dozens of experts told AP reporters.
Dr. Arthur Jey, an emergency services physician with Sutter Health in Sacramento, told reporters that getting out of the heat is important, along with wearing a hat and loose clothes, hydration and watching out for signs of heat stroke.
"With heat stroke, it looks like a stroke," Jey said, describing symptoms that may include acting unusual, significant headaches, blurry vision, profuse sweating and then no sweating.
"And that's a really big deal," Jey said. "So we want to prevent them getting even close to heat stroke."
California's heat was expected to spread from north to south over the week, with the worst of it focused on interior areas including the Sacramento and San Joaquin valleys and the southern deserts. But warnings extended out to just short of the coast.
The heat arrived with gusty, dry winds in the northern part of the state, where the utility Pacific Gas & Electric implemented public safety power shutoffs in parts of 10 counties to prevent wildfires from being ignited by downed or damaged electrical wires.
PG&E said about 12,000 customers were told their power could be cut and given information about centers where they could obtain ice, water, snacks, Wi-Fi and other necessities.
California has had a spate of spring and early summer wildfires feeding on abundant grasses spawned by back-to-back wet winters. The largest current blaze, dubbed the Basin Fire, was 17% contained Tuesday after charring more than 54 square kilometers of the Sierra National Forest in eastern Fresno County.
