NEW YORK (CBSNewYork/AP) — New York City opened cooling centers as temperatures were climbing into the 90s across the Tri-State area Wednesday, and no relief was in sight.

A heat advisory is in effect for New York City until 8 p.m. Thursday. In New Jersey, an excessive heat warning is in effect for Camden, Gloucester, Mercer and parts of Burlington until 6 p.m. Friday.

An air quality alert was also in effect for the entire Tri-State area through much of the day Wednesday.

As CBS2’s Lonnie Quinn reported the high topped out at 95 degrees in Edison, New Jersey; 94 in Bay Ridge, Brooklyn; 93 in New Brunswick, New Jersey; 92 in Cresskill, New Jersey; 91 in Central Park; and 87 in Riverhead, Long Island.

Even at 11 p.m. Wednesday, it was 83 degrees on the Upper West Side. The typical high for July 6 is 84 degrees.

But conditions will get even hotter on Thursday, Quinn reported. The forecast high for New York City for Thursday is 93 degrees – the hottest day of the year up to this point. Heat indices will make it feel like 95 to 100 degrees.

Pop-up storms are also expected Thursday, Quinn reported.

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To help beat the heat, more than 500 cooling centers will be open throughout the five boroughs until 8 p.m. Wednesday and will reopen at 8 a.m. Thursday. To find a cooling center near you, call 311 or visit www.nyc.gov/beattheheat.

Officials warn the hot and humid conditions could lead to heat related health issues, especially for the elderly and people in poor health. People are being urged to take extra precautions if they work or spend time outside, including drinking lots of water and wearing loose, light-colored clothing.

“Severe heat can be extremely dangerous – and all New Yorkers should think first and foremost about their safety and the safety of those around them,” New York City Mayor Bill de Blasio said. “Today we’re reminding New Yorkers: check in on friends, family, neighbors, senior citizens and those with chronic health conditions. As the weather heats up, find a place to cool down – and stay hydrated and protected from the sun until the heat passes.”

The Office of Emergency Management said it’s important for everyone to be on the lookout for symptoms that could lead to heat stroke.

“It’s hot dry skin, or cold clammy skin, confusion, disorientation, nausea, vomiting, trouble breathing, an excessively rapid heart beat,” said Dr. Oxiris Barbot of the city’s Health Department. “The effects of heat are really cumulative.”

As CBS2’s Dr. Max Gomez explained, heat-related illness is less common than it once was because there are many public places with air conditioning. But the U.S. Center for Disease Control and Prevention said there are still more than 600 heat-related deaths nationally, and many more heat illnesses every year.

Heat illness comes in a couple of types in escalating severity. By far, the most common is heat exhaustion.

The first sign of a heat problem is muscle cramps, which is a warning sign that you could be headed for trouble. Then, there is very heavy sweating, confusion, nausea or vomiting, a fast or weak pulse, and weakness or painting.

If you stop sweating and your skin gets hot and red, you could be on your way to heat stroke – a true medical emergency.

At the first sign of any such symptoms, you should move to a cooler location and lie down and apply cool, wet cloths to as much of your body as possible.

New York Giants quarterback Eli Manning, who knows how to stay cool in the heat and under pressure, also noted that it’s important to stay hydrated.

“Lots of fluids, lots of water, lots of Gatorade; replace those electrolytes, especially if you’ve been sweating, you’ve been outside moving around,” Manning said after taking part in a 45-minute drill with middle and high school kids at Kean University.

But Dr. Gomez said if your skin gets hot and dry, if you are vomiting, or if your body temperature is getting above 103 degrees, it’s time to get to an emergency room immediately.

When it comes to hydration, you should also examine your urine, Dr. Gomez said. If it is not clear or pale yellow, you need more fluids.

But even if people were taking precautions, the heat made for a nuisance all day Wednesday. Temperatures and dew points were rising even in the morning, creating a sticky commute for many.

“You just need like three showers just to maintain throughout the day,” Willie Cooper of Harlem told WCBS 880’s Marla Diamond.

Matthew Troupe, who works at Bryant Park for eight hours outside in the blistering heat, said he’ll take frequent water breaks inside.

“The heat makes the gravel hotter so it gets hotter in this section where I work at in the middle of the lawn,” Troupe said.

Marissa Bromann, of Carroll Gardens, was also ready to spend the day shopping with her friend.

“I decided to wear very light clothing. I brought my black hat because I don’t like the sun on my face and I brought my sunglasses,” she said.

New Yorkers could find relief at a pedestrian plaza at 39th Street and Broadway, where the Garment District Alliance set up comfortable chairs, laid out fake grass and served up cold lemonade.

“We have lemonade stands and we have water, and we’re handing it out and we’re trying to keep people cool with our tents and making them feel psychologically a little cooler with our grass,” said Barbara Blair, the group’s president.

On Long Island, many hit the beach at Robert Moses to keep cool.

“The sun and the breeze, it’s beautiful,” one beachgoer said. “And the water is nice and cool, also. The water’s refreshing.”

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