SACRAMENTO, Calif. -- Scorching heat pushed California's electricity supply to the brink Monday and threatened another round of blackouts as utility crews across the state struggled to restore power to tens of thousands of people left in the dark over the weekend.
Authorities warned that the eighth day of the heat wave could drive demand for electricity in California to an all-time high. Some businesses cut their power usage under a program that grants them lower rates if they agree to conserve during a crisis.
Meanwhile, utilities in the St. Louis area and New York City also labored to restore power to hundreds of thousands whose electricity was knocked out by storms and equipment failures.
California Gov. Arnold Schwarzenegger directed state agencies to reduce electricity use by 25 percent and turn off unnecessary equipment. He urged local and municipal governments and universities to do the same.
State energy managers issued a "stage one" emergency, warning they were dipping into reserve supplies to keep up with the demand for power.
"We're not sure we can go as high as the demand is looking like today," said Gregg Fishman, a spokesman for the California Independent System Operator, which manages the state's electrical grid. "It's going to be moment-to-moment through the afternoon."
Rolling blackouts were possible later in the day, said ISO president Yakout Mansour.
Monday's forecast called for high temperatures in central and Northern California of 111 degrees in Morgan Hills, 110 in Fresno, Stockton and Modesto and 109 in Bakersfield. In Southern California's Woodland Hills, the temperature was expected to reach 106. No relief was expected until at least midweek.
Authorities were looking into at least nine deaths in the smoldering Central Valley that may have been related to the heat. Among the victims was a Stockton nursing home patient who died from heat-related stress on Sunday after the Beverly Healthcare Center's air conditioning gave out, said police spokesman Pete Smith.
Tens of thousands of homes and businesses lost power in California on Sunday because of heavy electricity use and high temperatures that caused transformers and other equipment to overheat.
Some 50,000 customers in Northern California still were without electricity, including 35,000 in San Jose and the East Bay, according to Pacific Gas & Electric. About 20,000 Los Angeles customers also remained without electricity.
In Arizona, heat was believed to have contributed to the deaths of two homeless men in Phoenix over the weekend.
The deaths came during three days of record-breaking temperatures in Phoenix. The temperature soared to 114 degrees Sunday, breaking the record of 112 set in 1906.
Meanwhile, in St. Louis, more than 200,000 homes and businesses were still without electricity Monday, down from the more than a half-million that were left in the dark last week after strong storms knocked down power lines. Four deaths in the region were attributed to the storms or the heat.
Ameren Corp. Vice President Richard Mark said Monday that 90 percent of those without power could have the lights back on by Tuesday, with the rest expected to be back up by Wednesday.
The power company has been running TV commercials asking people to be patient. Some 4,000 utility workers from as far away as Arizona are restoring power around the clock, but many customers expressed frustration.
"You're supposed to have a backup plan in case something like this happens," said Dana Moorhead, who had no power Monday. "All my food's gone bad. Just going home is depressing."
In New York, thousands of Queens residents were facing their second week without power because of a blackout that at one point affected 25,000 customers. By Monday morning, electricity had been restored to about 22,000 of those homes, buildings and businesses, Consolidated Edison said.
The blackout has devastated the inventories of ice cream parlors, bodegas, groceries, butcher shops, fish mongers and restaurants. City officials estimated that at least 750 businesses were affected and said that the losses could reach into the millions of dollars.
At the Thai Pavilion restaurant, tables were set with water glasses and silverware, but the restaurant stood empty while other stores and restaurants started to get power again.
"I'm so jealous of the people who get to open," said Sam Arjariyawat, who manages the restaurant. "People will have to eat a lot of Thai food ... to help us out."
Associated Press Writers Christina Almeida in Los Angeles, Marcus Wohlsen in San Francisco, Christopher Leonard in St. Louis, and Adam Goldman and Colleen Long in New York contributed to this report.