The city is warning New Yorkers to take care and stay cool over the next few days, as the summer has its first heat wave.

The Health Department has issued warnings for heat illness for seniors and children younger than five years old.

Cooling centers will be open at locations throughout the five boroughs, including multiple senior centers, through Wednesday. It is the first time this summer that the cooling centers are open.

"People stuck in apartments absolutely have to get out if they don't have A/C, so we want to make sure people have a place to go," said Office of Emergency Management Commissioner Joseph Bruno.

Visitors to the center said they appreciate the air conditioning and the environment.

"A lot of people are not fortunate enough to have places where they can be comfortable and survive this oppressive heat," said one visitor. "It's a logical place for them to come."

"I'm a heart patient, I got to have something cool. I can't get overheated, it's very bad for me," said another. "And this place is a blessing, pleasant people to talk to, a good lunch."

"I have A/C in some of my rooms, in the kitchen and some of the other parts," said another. "But I need the exercise. They have a lot to offer for the seniors, which is good."

There are many other places than cooling centers where one can stay cool.

"If you can't get to one of the city cooling centers, visit a local library, or you can also go to the pool, maybe your local mall," said Amber Greene of Ready New York. "But definitely find places where they have A/C and you can stay cool."

Workers who are forced to stay outdoors found their own ways to beat the heat.

"I clean the streets, set up the tables and the chairs, change the garbage cans" said laborer Kema Sample. "I take it slow, drink plenty of water and take my breaks in the shade."

"I just got to stay hydrated, bear with it, drink a lot of water, keep yourself moisturized on the inside," said laborer Tamika Perkins. "I mean, it's doable. You can do it."

Meanwhile, OEM officials advised that today's visitors to the city's pools and beaches should drink plenty of water, wear light clothing and use sunscreen.

City officials also advise New Yorkers to avoid strenuous outdoors activity.

To find the closet cooling center, visit nyc.gov/oemor call 311.