As the death toll from a scorching heat wave rose and record demand tested the state's power supply, energy managers feared they may have to trigger rolling blackouts.

Authorities were investigating at least 29 possible heat-related deaths, most in the smoldering Central Valley where temperatures reached 115 degrees over the weekend and were forecast to remain in the triple digits for the next few days.

The intense heat pushed electricity usage to a peak of 50,270 megawatts on Monday — a record for California but still short of the 52,000 megawatts experts had predicted.

While government agencies and businesses so far have helped the state avoid rolling blackouts, energy officials expected another close call Tuesday.

"We still have our guard up," said Stephanie McCorkle, spokeswoman for the California Independent System Operator, which manages the state's power grid.

The ISO on Monday declared a "Stage 2" emergency, which called for some businesses to reduce their power usage in exchange for lower rates. Gov. Arnold Schwarzenegger also directed state agencies to reduce electricity use by 25 percent by turning off unnecessary equipment; local and municipal governments and universities were urged to do the same.

By Monday evening, the ISO had downgraded the emergency to a "Stage 1," relieving businesses that had agreed to reduce power, and later that night dropped the emergency declaration. But consumers were still asked to reduce their electricity consumption.

Gubernatorial candidate Phil Angelides criticized the Schwarzenegger administration for its handling of the state's energy resources.

"We shouldn't be asking businesses to shut down or the elderly to turn off their air conditioners," Angelides said in a conference call to reporters.

Schwarzenegger spokeswoman Julie Soderlund defended the state's utilities, noting they met California's power supply needs amid record temperatures.

Elsewhere, utilities in the St. Louis area and in New York City labored to restore power to thousands of customers whose electricity was knocked out by storms and equipment failures.

More than 200,000 homes and businesses in and around St. Louis were 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.

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.

"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."

Mark said some of the most critical damage was done to high-powered "feeder" lines that run from electrical substations to residential neighborhoods, where lower-capacity lines carry power to homes and businesses.

In New York City, thousands of residents entered their ninth day without electricity Tuesday, while the local utility worked around the clock to restore its service — and its image.

Consolidated Edison Co. said early Tuesday that about 1,000 customers in northwest Queens remained without electricity, a major improvement from the roughly 25,000 affected there at the height of the blackout but not enough to quell the anger over the outages. Officials have estimated there are four residents per customer, meaning 100,000 people might have been affected.

New York Attorney General Eliot Spitzer said that Con Edison "failed to heed the warnings" from an earlier blackout and that oversight of the utility has been "wholly inadequate."

Even former Mayor Rudy Giuliani chimed in on the situation during an appearance Monday on a sports radio program. When asked what he would have told Con Edison if he were mayor, Giuliani replied:

"I don't think I can say it on radio. I think you're going to have trouble with the regulators if you really want to know what I've been saying privately about that."