(AP) - Consolidated Edison closed walk-in centers, suspended meter readings and limited work on major construction projects in New York on Sunday after contract talks between the utility and its unionized workers broke down in the middle of a wave of extremely hot weather.

Negotiations stopped just before 2 a.m. Sunday, a couple of hours after the existing contract expired. The impasse came as New York braced for more high temperatures that will increase demand for air conditioning among the utility's 3.2 million customers.

On Sunday morning, police set up barricades in front of Con Ed's headquarters near Manhattan's Union Square.

"This is crazy! There's a heat wave," said David Palomino, a facility mechanic who rushed to headquarters after finishing his early shift to find out what was coming next. He was one of few workers there; a union official said more picketing was planned for Monday.

"The fight has escalated" between the two sides, Palomino said, explaining that workers fear losing chunks of their pensions and benefits.

Temperatures were in the 90s Sunday, with a heat advisory for the afternoon, and were expected to be in the high 80s and lower 90s in coming days.

At an electronics and air conditioning retailer across the street from Con Ed, manager Ramon Nieves said there have been multiple power outages in recent years in his Queens neighborhood.

"I'm mad at Con Ed - what are they thinking?" he said. "A lot of people could get sick in this heat."

He said his store sold about 35 percent more air conditioners this month than in the same, cooler period last year.

Frank Allen is making sure the heat doesn't blow his power at home in upper Manhattan. "I turn off the air conditioner when I leave home," said Allen, 61, who was shopping in the Union Square neighborhood.

"It's not too good when the wires go out, and there's no one to fix them, Allen said. "The workers should get whatever they deserve - just do it for us, Con Ed."

He has cats at home, but he's not worried leaving them without air conditioning. "They find their way to some cool corner."

And when he goes to work, heat is far from a problem: Allen works in a 33-degree space, in the refrigeration unit of the Fresh Direct food delivery company in Queens' Long Island City.

"In a heat wave, I wear long johns."

The extreme weather also included vicious storms from Indiana to New Jersey and south to Virginia that killed at least 13 people and left 3 million without power. Most of the damage came in the mid-Atlantic region, and only scattered outages across Con Ed's service area in New York were reported as of Sunday morning. Con Ed said it is keeping a close watch on its system and has trained managers working on essential operations.

The 8,500 unionized workers told the company they'd be willing to work without a contract to keep the power company running, said John Melia, spokesman for Local 1-2 of the Utility Workers of America.

"We did everything to avert this action," he said. "We recognize that New York City is sweltering right now. ... We recognize we have a responsibility to the people of New York City and Westchester County," the suburban county north of the city.

He disputed the company's claim that its managers could do the job of the union workers.

"They know what happens in a heat wave, they know they don't have the expertise to fix it," he said. "They don't have the technical knowledge."

Con Ed said it had wanted a two-week extension of the current contract while negotiations continued, with assurance that the union would not strike without notice. The company said it offered such an extension, signing an agreement to that effect, but that the union didn't sign it. Con Ed said if the union agreed to the extension, employees would be welcomed back.

Negotiations lasted just over 10 days over a range of issues, including pensions, heath care and wages.

"This is very unfortunate. Both sides are very far part," Con Ed spokesman Michael Clendenin said.

Melia said the union negotiators were kicked out of the room in what he called a "union-busting tactic."

"This is not a labor issue," he said. "This is a corporate monopoly."

He said the two sides had been talking when the company demanded the union sign the contract extension, and that Con Ed locked workers out when the union said it preferred to keep talking and keep workers at the jobs without a contract in the interim.

Melia said Harry Farrell, president of Local 1-2, on Monday plans to call on federal mediators to intervene and try to get talks started again.

He said union leadership would also be meeting Monday morning, and that picketing at Con Ed sites was planned.

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