The records are set up, ready to fall like dominoes if forecasters' predictions prove accurate for Southern California's heat wave this weekend.
On Friday, the National Weather Service expects heat records for July 7 in at least six parts of Los Angeles and Ventura counties to fall.
New records were set for the day in Palm Springs (122 degrees), Indio (119) and Thermal (121).
As of 3 p.m., downtown L.A. tied a heat record for the day, hitting 96 degrees. In Northern L.A. County, Sandberg set a new record for the day, 98 degrees.
Some of the areas that are traditionally hottest in L.A. County, such as Woodland Hills, may have consecutive days of record-setting temperatures. Woodland Hills is expected to reach 112 degrees Friday and Saturday, which would break and tie records for those respective days set in 2006 and 1985, the forecast stated.
As a result, the National Weather Service said there is a critical fire danger in the coastal mountains and foothills as well as an excessive-heat warning inland.
Members of the public were urged to avoid being outside directly under the sun in the midafternoon, and told to drink lots of water and to wear light-colored, lightweight clothing through the weekend.
The homeless, the elderly, infants, and people who work outdoors are particularly vulnerable to heat-related illnesses, officials said.
Los Angeles County's cooling centers are listed here.
Humans aren't the only ones who suffer in a heat wave. Pets can also be vulnerable to the sweltering conditions and can die if left in a vehicle for even a short time.
When it's 80 degrees outside, the inside of a car can heat up to 99 degrees in 10 minutes and climb up to 114 degrees in half an hour, the weather service said. A law that took effect this year allows Californians to break into vehicles to rescue animals if they appear to be in danger of excessive heat.
Of course, this being summer in L.A., the extra heat isn't shocking. But Bill Patzert, a climatologist for the Jet Propulsion Laboratory, said the heat waves are "definitely coming earlier this year."
Southern California typically sees its warmest weather in August or September, he said.
The sizzling temperatures are the result of a jet stream that brings cooler weather to the California coast, moving north due to the position of the sun relative to the Earth in summer, Patzert said.
That shift produces the American Southwest monsoon, in which high pressure settles over the Four Corners region of the U.S. — where Arizona, Utah, New Mexico and Colorado meet — and pulls in tropical moisture from the Gulf of California and warm air from the Mexican desert.
The system is currently settled over the desert in the Southwest and spreading sweltering temperatures from California to Oregon and as far east as central Texas.
The mixture of heat and humidity makes it difficult for the human body to insulate itself from the heat in the shade. It also increases the chances of thunderstorms that will produce dry lightning and spark wildfires.
"This one is more intense than we saw in June … and so the danger to the vulnerable just got maxed up," Patzert said of the heat wave.
4:40 p.m.: Updates with Palm Springs record.
3:29 p.m.: This article was updated with information about afternoon temperatures.
11:40 a.m.: This article was updated with authorities' suggestions on dealing with the heat.