And on the worst days she heads to New York Sports Club on East Park Avenue or Pure Fitness in Island Park, where she works with a personal trainer. But compared with the boardwalk, the gym treadmills are drudgery. “I hate it,” she said. “I’m counting every minute that goes by and the calories I’ve burned. The time really flies when you’re outside, especially on the boardwalk because the scene is so beautiful.”

Part of what pushes Koff to run in the cold is a philosophy, one she imparts to her clients in therapy, that says to get up and move move every day, whether to run, skip rope or just walk.

Having the right gear, especially the right hat and gloves, she said, is key to exercising outside when the mercury heads south.

Katie Sell, an exercise physiologist at Hofstra University and a Long Beach resident, concurs. In cold weather the body directs blood and heat to vital organs such as the brain, heart and liver, Sell explained, so wearing the proper hat, gloves and even socks becomes especially important. Dressing warmly protects runners not only from frostbite, but also from decreased sensory ability, she said.

Sell suggested that cold-weather exercisers like Moriarty and Koff wear materials that “wick” sweat away from the skin, which is especially important in the cold, and that they dress in layers.

“Advanced runners know to wear a long-sleeved shirt and a T-shirt, and then another long-sleeved shirt, while a new runner will put on a T-shirt and a big heavy fleece,” she said. “But you can shed the layers as your body temperature goes up, and also they don’t get damp from sweat so you can put them on afterwards.”

Sell, a native of England, is used to exercising in cold weather, though a bum knee has sidelined her running routine, so she plays tennis in the winter.

She makes sure that she always has water, even in sub-freezing weather, to stay hydrated. “You should bring a bottle of water with you, but not ice-cold water,” Sell said. “You have very delicate tissue in the back of your throat, and in the cold air it needs to be warmed a whole bunch more. Tap water is good.”