June 19, 2016: Hotel guests cool off at the pool at the JW Marriott Scottsdale Camelback Inn Resort and Spa in Paradise Valley, Ariz.
At least four deaths have been attributed to the sweltering heat that has plagued Arizona this weekend.
The Arizona Republic reported that four hikers collapsed and died on trails across the state. One hiker died in the Phoenix Mountain Preserve, another died on the Peralta Trail in the Superstition Mountains, a third near Finger Canyon Rock and a fourth in Ventana Canyon.
"It really shows how critical this heat can be and how it can really sneak up on you," Phoenix Fire spokesman Capt. Larry Subervi told the paper. "When we deal with temperatures like this, it can just really be unpredictable how your body is going to respond."
The blistering heat broke records across the state Sunday. Temperatures in Phoenix, Flagstaff, Tucson and Yuma broke daily records, according to the National Weather Service. Phoenix topped off at 118 degrees, Tucson at 115 degrees, Flagstaff reached 93 degrees and Yuma was scorching at 120 degrees.
According to the Arizona Republic, temperatures sharply rose Sunday morning and the records started to shatter by noon. Yuma topped the mercury off at 117 by 12:20 p.m. The daily high of 120 degrees ties the city's fourth-highest temperature.
Phoenix peaked at 118 degrees over the course of the day, the fifth-hottest day on record. The highest point on Tucson's mercury read 115 by 3:13 p.m. Flagstaff broke a daily record with 93 degrees and Prescott reached 102 degrees over the course of the day.
Even with the blistering heat, some still ventured outside to run errands. Kim Leeds, 28, had to take her dog Bo outside in the early afternoon for a bathroom break. The Australian shepherd wears special booties with rubber bottoms.
"He does really well with them. He doesn't mind walking around," Leeds said.
Preparing to enter her fourth summer in Phoenix, Leeds also decided to experiment with her car.
"I'm totally reveling in this experience because I'm actually baking cookies in my car," Leeds said. "I've been here long enough that I've got to do these things."
Others took advantage of discounts at Phoenix-area resorts, where summer can be the slow season.
Hotel guests got an early start at the JW Marriott Scottsdale Camelback Inn Resort and Spa as temperatures climbed. Several guests swam in the pool and sat under umbrellas sipping water and other iced drinks to cool off.
Phoenix isn't expected to get cooler by Monday. Andrew Deemer of the National Weather Service in Phoenix told the Arizona Republic that the center of the high pressure system in the west is supposed to will be located just outside the city.
He added that Phoenix could be looking at temperatures in the low 120s. The state's all-time heat record is 122 degrees set in June 1990.
With the heat not expected to die down, officials urge residents to learn the signs of a heat-related illness. Symptoms could include thirst, cramps, heavy sweating, nausea, headache and dizziness.
Southern Californians also posted competing photos on Facebook and Instagram of their soaring thermometers as the last day of spring brought summerlike temperatures to the region.
Burbank and Glendale, just north of downtown Los Angeles, soared past 100 degrees by midday, the National Weather Service said. Burbank saw a record 105 degrees.
That heat was no help to firefighters who had to work to put out a wildfire in a Los Angeles neighborhood, where densely packed homes were briefly in danger.
Further northwest in the San Fernando Valley, some thermometers were reading close to 110 degrees, and Palm Springs in the inland desert hit 115.
The heat spurred state regulators to urge residents to voluntarily cut their consumption of electricity Monday. It did not yet bring the rolling blackouts that might Southern Californians have been told to expect this summer after a massive natural gas leak.
The Associated Press contributed to this report.