Beaches and pools will remain open longer and people should prepare themselves for brutal heat through the weekend, officials said.

Nassau County said a cooling center at the Mitchel Field Administration Center in Uniondale would be open from 9 a.m. to 4:45 p.m. Friday. The Town of Oyster Bay said the Hicksville Community Center would be available as a cooling center from 9 a.m. to 7 p.m. Friday.

With air heavy with humidity, conditions will feel more like 100 to 105 degrees — even higher in Nassau County, the National Weather Service said.

At just before 2 p.m., the temperature at Long Island MacArthur Airport was 89 degrees, but felt like 100, thanks to the humidity, according to weather service data. With a temperature of 91, Farmingdale felt more like 105, and Shirley was registering 87 degrees, feeling like 98.

The service has issued an excessive heat warning for Nassau and northwestern Suffolk through 10 p.m. Sunday, with heat index values — also known as “feels like” temperatures — of 105 to 110.

Other parts of Suffolk are under a heat advisory, meaning the humidity could make it feel more like 100 to 104, through 8 a.m. Saturday. An excessive heat watch will be in effect from then until Sunday evening.

The New York State Office of Parks, Recreation and Historic Preservation said it will offer extended hours at its parks and swimming facilities through Sunday.

State health officials cautioned people to be on the lookout for signs of heat-related illness, such as hot, dry skin, heavy sweating and muscle cramps.

People should minimize outdoor activity, drink plenty of water and try to stay in an air-conditioned place, the health officials said.

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Also, people should not leave pets or children unattended in parked vehicles during peak heat periods, when temperatures inside a closed vehicle can reach 140 degrees quickly, the officials said.

The state Health Department offered these other specific recommendations:

  • Open shades and windows on the shady side of your residence and close them on the sunny side.
  • Wear loose, lightweight and light-colored clothing.
  • Wear sunscreen and a ventilated hat outdoors.

With Patricia Kitchen