The Los Angeles County coroner Thursday updated the number of deaths from last week's heat wave to 18, bringing the total to 31 throughout the Southland.
The 18 deaths occurred across a wide section of Los Angeles County, including the San Fernando Valley, the Fairfax district and downtown. Seven victims were found in Imperial County, five in San Bernardino County and one in Riverside County.
The newly reported deaths include a 40-year-old Newhall man found Wednesday afternoon in his home in the 23000 block of Lyons Avenue by officers who had been asked to check on him by concerned friends.
"One of the residents there in the neighborhood said the decedent was complaining a few days ago about leg cramps and the heat, and the air conditioning was not functioning," said Los Angeles County coroner's spokesman Capt. Ed Winter.
Another victim, a woman in her 50s, was found dead Thursday morning in her bedroom at a Long Beach board-and-care facility, he said.
"In terms of human health, these heat waves are worse than El Niños or La Niñas," JPL climatologist Bill Patzert said. "Air quality plummets, temperatures skyrocket, and it really takes a toll on pets, young children, the elderly, or anybody that has any kind of health condition."
The heat wave, which sent temperatures soaring into the triple digits, was caused by a high pressure system above much of Southern California that blocked out the marine layer from the Pacific Ocean and stopped the usual cool breezes from entering the region, Patzert said.
Temperatures remained high during the nights, further straining an already overburdened power supply.
Patzert said such high nighttime temperatures occur 20 to 40 days a year, and as average temperatures appear to be on the rise, more people suffer since more people live in urban areas.
August historically has had the highest average temperatures, Patzert said, but September has had the most extreme temperatures and is considered a heat wave month.
"I hope it's not," Patzert said, "but it's entirely possible that this is a preview of coming attractions."