NEW YORK (CBSNewYork/AP) — Temperatures soared into the 90s again Wednesday, putting incredible demand on the power grid and leaving some sweating in dark rooms.

A heat advisory was in effect until 8 p.m. Thursday, for New York City. An excessive heat warning is also in effect in New Jersey from noon until 6 p.m. Thursday for Mercer, Gloucester, Camden and northwest Burlington counties.

READ MORE: Wild Roll To Win Against Devils

The temperature on Wednesday topped out at 96 degrees, with heat indices making it feel as hot as 105 degrees in some places, CBS2’s Lonnie Quinn reported.

As CBS2’s Vanessa Murdock reported, most New Yorkers seemed to take the soaring temperatures in stride Wednesday. But those who woke to no power and no air conditioning Wednesday morning were not so pleased at all.

CHECK: Forecast | Cooling Centers | Safety Tips

By mid-morning, Con Edison was reporting hundreds of power outages in the Crown Heights and Prospect Park sections of Brooklyn, the Flushing and Jamaica sections of Queens and the Chinatown section of Manhattan. As of 11:50 a.m., Con Edison was reporting 1,144 power outages in Brooklyn alone.

“It’s warm and hot,” Crown Heights resident Bathel Predelus told CBS2’s Andrea Grymes. “There’s no air conditioning.”

By 4:15 p.m., the outages had been reduced to 49 in Brooklyn, and 30 in the Bronx. But the hours of misery with no air conditioning had been enough for many.

“One of the hottest days of the year,” said Ted White of Crown Heights, Brooklyn. “Please, Con Edison. Help us, please.”

White was one of more than 800 Con Ed customers along Union Street who went most of the night without power. It was an experience that neighbor Stewart Finck described as “unbearable.”

“In fact, I had no choice. In the middle of the night, I had to go to my brother-in-law’s house to sleep,” Finck said. “Even with a fan, it’s horrible. Without anything you can’t bear it.”

For business owners, restoring power means preserving their bottom line.

“I have a computer company over here,” one man said. “I can’t open my door. My garage, my electricity, my whole business is shut down right now. We’re losing money.”

The owner of the Albany Bakery, who didn’t want to speak on camera, said the fact that the power has been out for more than 12 hours is ridiculous. He said he’s losing business and money, and it’s not the first time: Just two weeks ago, he had to throw out thousands of dollars of food from the freezer.

Meanwhile, just across the street, a dry cleaning business got lucky. In a gesture of goodwill, a neighbor ran an extension cord so the business could open.

“This is just inexcusable,” Finck said. “It’s like a Third World country what’s going here with Con Edison.”

Meanwhile in Ossining, a 13,000-volt feeder cable sizzled through the pavement and caused a fire in the street at the Old Albany Post Road and Route 9A in Ossining as power demand hit its peak, CBS2’s Lou Young reported.

Hundreds of customers were also without power in Wayne, New Jersey, including an entire nursing home.

Con Edison spokesman Michael Clendenin told CBS2 that getting electricity back up and running was the main priority.

“Our goal during heat waves like this is to try to keep the outages small in number; short in duration,” he said.

By noon, Con Ed did get the power back on and business boomed in Crown Heights once again. Resident Pinchus Goldin said things grew “much cooler.”

Mayor Bill de Blasio urged New Yorkers to try to limit their energy consumption by setting their thermostats to 78 degrees. He says it’s everybody’s responsibility.

“As the temperature goes up, so does energy usage, and that creates the danger of blackouts and brownouts,” the mayor said at a news conference. “And we do not want to see that happen in this city on any major scale.”

As CBS2’s Dave Carlin reported, the heat also posed a serious health risk. The emergency room at Mount Sinai Roosevelt Hospital was full of people who failed to beat the heat.

“The patients that have been out getting exposed to the sun and the heat are really coming in with a myriad of different symptoms — headaches, sweating, fatigue, nausea, generalized weakness, even leg cramps; body cramps; even abdominal pain as well,” said Mount Sinai emergency medicine Dr. Shefali Trivedi.

The doctor’s advice is to find someplace cool. But that mission was a sweaty challenge in the areas with heat-related power problems.

Among the heat wave surprises were high surface temperatures in parks and playgrounds. Geoffrey Croft, president of NYC Park Advocates, showed CBS2 the problem – starting with a field of artificial turf.

“These fields on a day like today are heading up to upwards of 165 degrees,” Croft said.

As late as 5 p.m., the field was still too hot.

READ MORE: DeRozan, LaVine Help Bulls Hang On To Beat Knicks

“We’ve got 121 degrees, and this is late, late afternoon,” he said.

Nearby, some asphalt on which kids were playing reached 126 degrees. By comparison, a slick surface on the park’s water feature was only 66 degrees.

In anticipation of the higher energy demand, the New York Port Authority and the Metropolitan Transportation Authority activated a summer program to reduce electricity.

The Peak Reduction Program can be operated for up to 15 days between June 1 and Sept. 30, officials said.

It commits the MTA to lower electricity use at 28 New York City Transit bus depots, all New York City Transit substations and one rail service yard during the highest-demand days to help ensure reliable supplies of electricity.

Mass transit service will not be affected, officials said.

“The MTA is pleased to be able to work with NYPA to help reduce peak loads during the increasingly challenging summer days,” Thomas F. Prendergast, MTA chairman and chief executive officer, said in a statement. “We are committed to doing everything we can to help ensure that people in New York City have reliable access to the electricity they require for their homes and businesses while serving the daily transportation needs of millions of our customers.”

Wednesday’s heat and humidity will likely mean public swimming pools will be packed again as people look for ways to cool off. The city said it is extending pool hours until 8 p.m. Wednesday.

The FDNY hopes to help people beat the heat by applying sprinkler caps to hydrants when requested by an adult resident. They cut the amount of water that spills out from 1,000 gallons per minute to 25.

“Our main concern is fire protection and we also all understand we were all kids, too, once playing in the streets. And we understand kids want to get cooled off,” said FDNY Deputy Chief Jay Jonas.

For those looking to beat the heat at the beach, there is a moderate risk for dangerous rip currents in Ocean County, New Jersey. There is an elevated low risk along the rest of the Jersey shore.

De Blasio urged people to drink plenty of water, stay in air-conditioned places and limit their time in the sun if they do go outside. He asked New Yorkers to check on their neighbors who are elderly or may have health conditions.

For those who don’t have air conditioning, the city has opened more than 500 cooling centers across the five boroughs. To find a cooling center near you, call 311 or click here.

Around the area, people found a variety of ways to deal with the heat. At the Prospect Park farmers’ market, the produce stayed perky despite the heat and the fish remained fresh.

“I’m doing OK; I’ve just got to take it a little slower and let him do most of the work — the young guy,” said fishmonger Stephen Carroll of Montauk-based American Pride Seafood.

Some Brooklyn residents were pleased that there was just a bit of a breeze.

“It’s really warm, with maybe a tiny bit of wind,” said Emily Weassman, 9.

Sojourner Storey said that tiny bit of wind sure did help, but she was still wiping the sweat off her chin.

“It is killer out here,” Storey said.

On Long Island, many people got their jogs in on the Jones Beach boardwalk early Wednesday morning before the heat turned up.

“It’s not too hot yet, so we’re still good and I have my water, I have my sunscreen,” Ruthann Druids of East Northport said told WCBS 880’s Mike Xirinachs.

Meanwhile, in Coney Island, Brooklyn, it felt like a built-in air conditioner coming off the water, 1010 WINS’ Glenn Schuck reported.

“We’ve got the air moving, so it’s great,” said Mike from Sunset Park, Brooklyn, who was with his 6-year-old daughter. ” … It helps a lot to get out of the apartment.”

Also in Brooklyn, Frenchie Greene of Clinton Hill said he would appreciate a pool.

“If a kiddie pool was right here, would you jump in?” CBS2’s Murdock asked him.

“I’d jump in — no problem,” Greene said.

Murdock herself said she would too. At no point in her travels Wednesday did the thermostat read below 90 on the Mobile Weather Lab.

And the National Weather Service says temperatures are likely to remain in the 90s for the rest of the week, however it is expected to be less humid on Friday.

MORE NEWS: Karlsson Scores In OT To Give Sharks Win Over Islanders

(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)