Nine-year-old Luis Dasilva held a towel over his head, wiping the sweat off his brow, as he waited in a long line under a sweltering Saturday sun to get into the Hollywood Recreation Center's pool. "It's just too hot," he said.
A half-hour later, he rushed to the water slide in his purple and gold Lakers swim trunks.
"Last year wasn't this crowded," pool manager Windie Beranek said of opening day. "But it also wasn't this hot."
On the second official day of summer and the fourth consecutive day of the heat wave, hundreds of thousands of Angelenos flocked to city pools and beaches as temperatures rose to triple digits in many areas.
The beaches from Malibu to Marina del Rey had about 500 lifeguard rescues Saturday, said Capt. Terry Harvey, a spokesman with the Los Angeles County Fire Department's lifeguard division. One woman was hit by a lifeguard vehicle at Manhattan Beach and was taken to a hospital with noncritical injuries, Harvey said. The woman was later released, authorities said.
The Los Angeles Department of Water and Power had 50 crews working to restore power to about 4,000 customers in North Hollywood, Canoga Park, Reseda, Northridge and other areas.
Saturday's demand, which peaked at 5,383 megawatts, broke a weekend day record of 4,682 megawatts set in June 2006, said Joe Ramallo, a DWP spokesman.
Southern California Edison crews were working to restore power to about 2,200 customers mostly in Lake Elsinore, Corona, Whittier and Altadena.
"This is a combination of extreme heat and, consequently, extraordinary demands for energy and a strain on our system," Ramallo said. Officials urged people to avoid running major appliances in the afternoon, when energy demand is highest, and to keep thermostats at 78 degrees.
Temperatures today are expected to hit triple digits inland and reach the 80s and 90s in coastal areas, with cooling forecast for Monday, when a marine layer is expected to roll ashore, according to the National Weather Service.
The heat wave has been the result of a high-pressure system above the Los Angeles area and weak offshore wind that trapped heat over land, said Bonnie Bartling, a specialist with the National Weather Service in Oxnard.
Residents who didn't want to make the drive to the beach started lining up outside the Hollywood Recreation Center an hour before the pool opened at 1 p.m.
"It's closer, and gas prices are too high," said Jose Gonzales, 35, a maintenance worker from Hollywood who walked to the pool with his son, Louis, 16, and daughter, Rosie, 9.
Beaches were packed and parking lots full throughout the day.
Water temperatures were in the low- to mid-60s, said Lifeguard Section Chief Garth Canning. South-facing beaches, such as Santa Monica and Manhattan, were seeing 3- to 4-foot waves, he said.
"So there are rip currents pulling," Canning said. "People should always go up and talk to lifeguards" about the safest spots to go in.
"All the variables aligned today," lifeguard spokesman Harvey said late Saturday. "We had no wind, we had a southwest swell mixing with a little bit of northwest wind swell . . . We were extremely busy throughout the day, starting at 9 a.m."
Attendance was "outrageous," he added.
"The berm was littered with people with umbrellas, just a thick line of umbrellas coating our beaches," Harvey said, after patrolling from Cabrillo Beach in San Pedro to Marina del Rey.
The swells will probably drop today, with 2- to 3-foot waves, Harvey said.
Health officials advised people to drink plenty of water but to avoid caffeine and alcohol, which can cause fluid loss, and to drink fruit juice or sport drinks to replace salt and minerals lost through sweat. Children, the elderly and pets should never be left in an enclosed vehicle, even briefly, officials said. Temperatures can quickly rise to life-threatening levels even with the windows partly open.
Times staff writer Deborah Schoch contributed to this report.