As a heat wave envelops the West, 32 million people from Texas to California are on alert for life-threatening temperatures.
Thursday and Friday will be the hottest days, when temperatures could surpass 110 degrees in some places.
MORE: Climate officials mark World Environment Day by announcing 12 months of record high temperaturesRecord highs were recorded in Texas on Tuesday, including 111 degrees in San Angelo and 109 degrees in Del Rio.
On Wednesday, temperatures are forecast to soar to a scorching 109 degrees in Phoenix and Palm Springs, California; 108 degrees in Las Vegas; and 105 degrees in Tucson, Arizona, and Fresno, California.
MORE: Heat stroke vs. heat exhaustion: Extreme heat safety tipsIf Las Vegas hits 112 degrees on Thursday, it’ll be the city’s hottest temperature ever this early in the season.
The dangerous heat will spread north by Friday and Saturday, with record highs possible in Oregon, Idaho and Colorado.
Doctors recommend taking excessive heat warnings seriously. There are hundreds of deaths each year in the U.S. due to excessive heat, according to CDC WONDER, an online database, and scientists caution that the actual number of heat-related deaths is likely higher.
Click here for what to know about staying safe in the heat.