Thanksgiving could be dangerously cold, experts say. Here's what to do.

Thanksgiving Day promises to be blustery and dangerously cold — we’re talking about temperatures around the mid 20s, feeling more like the low teens with gusting winds. 

Those wicked temperatures are around 25 degrees below normal and could set records, the National Weather Service and other forecasters said.

We don’t have to worry much about those watching parades and tending to turkeys indoors, feeling toasty warm. But the more adventurous — out watching friends toss footballs in turkey bowls or shivering in place along the route of the Macy’s Thanksgiving Day Parade — will need to take care. With northwest winds gusting to 25 to 30 mph, it will feel more like the single digits in Manhattan at parade time.

“When you are exposed to cold temperatures for long periods of time, you will eventually use up your body’s stored energy, which leads to hypothermia,” said Dr. James L. Tomarken, commissioner of the Suffolk County Department of Health Services.

To address that, Carlie Buccola, an Upton-based weather service meteorologist, has one word: layers, repeated many times.

She’ll be at the parade Thursday, holed up inside a command bus to support New York City emergency managers with in-the-moment weather information. Still, she knows from beating the cold, recalling an Islanders game in Yankee Stadium with temperatures in the teens.

You’ve got to “layer up,” she said. With “layer upon layer upon layer,” she was so well prepared for that game that, she said, “I was actually comfortable.” That included a winter coat, hat and snow pants.

"Take care to bundle up warmly if you are planning on attending the parade," said Dr. Oxiris Barbot, acting New York City health commissioner. Though everyone who is outdoors is at risk for hypothermia, the homeless and those who drink heavily or use drugs are at increased risk for injuries, illness or death, she said.

Gov. Andrew M. Cuomo's office also advised New Yorkers to prepare for the "extreme cold in the coming days" with layers of loose, lightweight clothing. 

“Outer garments should be tightly woven, water repellent and hooded,” with mittens, snug at the wrist, preferable to gloves, as “fingers maintain more warmth when they touch each other,” Cuomo's office said in a statement. 

Given the early blast of arctic air and Long Islanders not yet feeling acclimated to the cold, weather service meteorologist Jay Engle said preparing for extreme cold would not be out of order for those planning to be outdoors for any length of time.

The weather service in a graphic provides guidance for cold-weather dressing, ranging from chilly to cold to extreme cold conditions.

That includes a warm hat; face mask; three or more top layers, one insulating you from the wind; two or more bottom layers; gloves; and waterproof boots, all for the most severe cold.

You need so many layers, Buccola said, because “once you get a chill, it’s very hard to get warm again when outside.”

When the body cools down, it “can affect your brain, making it difficult to think clearly or move well, which makes it especially dangerous because a person experiencing hypothermia may not know that it is happening,” Tomarken said.

That means keeping an eye out for others. “If you notice someone shivering, confused, and with slurred speech, get the person to a warm room, offer a blanket and warm beverages, and get medical attention as soon as possible,” he said.

Of course, those participating in 5-mile runs and passing footballs back and forth generate some heat from all that activity.

Be it “snow or rain or shine — or cold or hamstring [issues], we are there,” said Jess Rudolph, 60, of the annual Thanksgiving turkey bowl, now in its 43rd year, for which he and his former Jericho High School classmates assemble.

Still, with a nod to the cold, he said jokingly that “the number of plays will equal the wind chill factor,” so if it feels like 7 degrees, each side gets seven passes.

Actually, at this stage, about as much kibitzing gets done before and after the game as actual play, he said. “This year, there’ll probably be a little more kibitzing and a little less football.”