SACRAMENTO, Calif. (AP) – The death toll from a 100-plus-degree heat wave continued rising Tuesday as utilities renewed their pleas for energy conservation to avoid rolling blackouts.

Slightly cooler temperatures were expected in California, thought the misery index remained high: temperatures in the Central Valley were expected to reach 100 to 105 on Tuesday, compared to 110 to 115 during previous days, the National Weather Service said.

Authorities were investigating at least 34 deaths possibly caused by the heat, most in the steamy Central Valley. Officials said most of the victims were elderly.

Thousands of farm animals also were dying in the heat, officials said.

In St. Louis, Mo., were more than 150,000 customers have been suffering through a weeklong heat wave without electricity, one utility worker was electrocuted Tuesday after stepping a downed powerline that had been obscured by branches, and another suffered electrical burns, utility Ameren Corps said.

Thousands of New Yorkers were also still without power in the ninth day of a blackout, with no clear estimate of when all the services might be restored.

The worst of the heat this week has been in the West, where California air conditioners drove electricity use to 50,270 megawatts on Monday _ a state record. Cutbacks by government agencies and businesses helped avoid rolling blackouts, but energy officials expected more strain on the system Tuesday.

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

ISO officials warned that they were likely to issue another “stage 1” emergency, calling upon consumers to conserve electricity. An elevated “stage 2” emergency, where businesses voluntarily reduce power use in exchange for lower rates, was also possible, said Gregg Fishman, an ISO spokesman.

Utilities in St. Louis and New York were still laboring to restore power to thousands of customers whose electricity was knocked out last week by storms and equipment failures.

About 158,000 homes and businesses in the St. Louis area were still without electricity Tuesday, down from the more than a half-million blacked out by storms last Wednesday and Friday. Five deaths were linked to the storms and heat, including the utility employee electrocuted Tuesday while working to restore power.

Ameren Corp. Vice President Richard Mark said Monday that 90 percent of those without power in St. Louis could have the lights back on by Tuesday, and most of the rest on Wednesday. Temperatures, meanwhile, were expected to reach into the 90s.

“All my food’s gone bad. Just going home is depressing,” said St. Louis resident Dana Moorhead.

In New York, the utility worked around the clock to restore its service _ and its image.

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

In Northern California, an estimated 25,000 customers remained blacked out Tuesday, down from 119,000 on Monday, Pacific Gas & Electric reported. It was the third day without power for about 1,700 San Jose customers and some people slept outdoors or went to air-conditioned hotels to beat the heat.

The heat also has been hard on farmers, causing thousands of livestock deaths, according to state agriculture officials. Milk production in California, the nation’s No. 1 dairy state, is down by as much as 15 percent because of the heat, according to the California Farm Bureau.

In the San Joaquin Valley, The combination of the heat, big dairy herds and few plants equipped to properly dispose of dead animals created a backlog of rotting carcasses.

“They’re just sitting out there in the sun, drawing flies,” said Fresno County dairy farmer Brian Pacheco.