PHOENIX (AP) - The National Weather Service declared an excessive heat warning for the Phoenix area for Sunday and Monday, reminding people to stay cool at the beginning of Arizona's dangerous summer season. The federal agency has also issued a similar warning for some desert areas of eastern California.
The forecast in the Arizona capital called for highs of 106 to 110 degrees Fahrenheit (41 to 43 degrees Celsius) both days, with lows in the 70s (20 degrees Celsius).
The metro Phoenix area, with some 5 million residents spread across the aptly named Valley of the Sun, experiences temperatures higher than 100 degrees Fahrenheit (37 degrees Celsius) most summer days. The weather agency uses a complicated formula to declare an excessive heat warning, including close to record-breaking temperatures. The official high Sunday was 108 degrees Fahrenheit (42.2 degrees Celsius), the National Weather Service reported.
Weather service meteorologist Mark O' Malley said the current excessive heat warning was also issued for eastern desert areas of neighboring California, including around Joshua Tree National Park and the cities of Palm Springs and El Centro.
"This is not uncommon, it isn't even a record for us," O'Malley said Sunday. "But it is hot, 10 degrees above average.
"We have this every year, but every year we have lots of people succumb because of the heat," he added. "It's a dangerous heat. Take all the precautions, checking on your neighbors, and be smart out there."
Phoenix officials on Friday launched a safety campaign for Arizona's brutal summer season, calling on people in one of the hottest major U.S. cities to protect themselves from extreme heat that can be deadly as temperatures regularly creep into triple digits.
The National Weather Service last week teamed up with the Arizona Department of Health Services and other government agencies to launch a heat awareness campaign.
"Periods of excessive and/or extreme heat are no joking matter," the weather service said on its website. "Heat kills more people than tornadoes, floods, hurricanes, earthquakes and lightning combined."
There were 155 heat-associated deaths reported in Phoenix's Maricopa County in 2017, the highest annual number ever recorded, as the city experienced the warmest year on record.
According to the Arizona Department of Health Services, 219 people died from heat-associated causes around the state last year, with nearly 1,300 heat-caused deaths statewide during the decade from 2005 to 2015.
The department said that last year more than 2,874 people visited hospital emergency rooms for heat-related illnesses such as heat exhaustion and heat stroke, mostly in the southern and western parts of the state spread across the Sonoran Desert.
The heat is especially dangerous for people spending time outdoors without bringing along sufficient water or taking other precautions. That's especially true on the many popular hiking trails in and around the city, including on landmark Camelback Mountain.
On Sunday morning, Phoenix, Tempe, and Scottsdale firefighters were summoned to Camelback's Cholla Trail to help a 30-year-old woman suffering from heat-related issues. The Phoenix Fire Department said when the first crew got there they found the woman in stable condition but then came across a man with moderate heat exhaustion who had to be transported to the hospital.
The Salvation Army in Phoenix said it would activate its heat relief stations throughout the metro area where people can go for cooling and hydration through Monday evening. It said mobile hydration units would be dispatched to certain areas with large populations on homeless people and others vulnerable to excessive heat.
It said it served 400 people on May 6 when the National Weather Service declared its first excessive heat warning of the year for Phoenix.