PHOENIX A potentially deadly heat wave is expected to bear down on some Arizona and California desert areas in the next few days, forecasters said on Wednesday.
The mercury is predicted to soar well past 110 degrees Fahrenheit and perhaps top 120F (40s and 50s degrees Celsius) starting on Friday in the deserts of southeast California and southern Arizona, Weather.com and the National Weather Service said.
Forecasters said highs could top 118F (48C) in Phoenix on Saturday, potentially setting a new record for that date in the sun-baked Arizona capital, and increasing the risk of heat stroke and exhaustion.
"Exceedingly high temperatures can cause heat-related illness, including death," the National Weather Service said in an excessive heat warning.
The agency added that residents without air conditioning are most vulnerable during the period covered by the warning - 8 a.m. on Friday through 8 p.m. on Sunday.
Another concern is the risk to undocumented immigrants trekking up from Mexico on foot through the remote deserts of southern Arizona, where shade is scarce and heat is expected to reach 115F to 121F (46C to 49C) over the weekend.
"It's a very dangerous situation to have anyone out in these remote areas," Brent Cagen, a spokesman for the Tucson sector of the U.S. Border Patrol, told Reuters. "We definitely see a rise (in rescues and deaths) when it gets to be 115 or 120 degrees (Fahrenheit) out in the desert," he added.
Agents, including 250 specially trained as emergency medical responders, carried out 374 rescues from October 1 through May 31. Ninety-nine deaths, most from exposure, were reported during the period, Cagen said.
(Reporting by Tim Gaynor; Editing by Alex Dobuzinskis and Stacey Joyce)