5:34 p.m. EST January 18, 2014 SATELLITE BEACH, Fla. How cold are Florida winters? It's all in your head, a New York cardiologist says. Back hunched against the breeze, Wendy Holzinger stuffed her hands deep into the pockets of her white hooded sweatshirt for warmth while she searched for sea glass at Pelican Beach Park.

It was a Space Coast wintry afternoon earlier this week: brilliant sunshine, cloudless skies and 57 degrees.

"It's a chilly day, yes. I would not go outside without a jacket," the Patrick Air Force Base resident said. "If I wasn't in the sun, and I didn't have jeans and a jacket on, it would be freezing."

But just 50 yards up the beach, Ellen Reimer disagreed. The vacationing Seattle resident sunbathed barefoot on a beach towel.

"I don't think it's cold. I have noticed people bundled up," said Reimer. "I heard on the news that people should bring their pets and their plants indoors — and I'm like, it's 50 degrees."

Countless Northerners who endured this month's bone-chilling, sub-zero "polar vortex" scoff at the thought that local residents even experience wintertime cold.

Regardless, some residents are bundling up in Minnesota-worthy parkas, knit caps, gloves and scarves — during quick trips to Starbucks and Winn-Dixie.

Why? Well, according to popular legend, your blood "thins" after you move to Central Florida's muggy subtropical climate.

That's hogwash, according to Dr. Holly Andersen, a cardiologist and director of education and outreach at the Ronald O. Perelman Heart Institute of New York-Presbyterian Hospital.

Rather, Andersen said sensations of hot and cold weather primarily originate from a large internal thermometer: the brain.

"Most of it comes from our supratentorial, our white matter, our cortex, our higher thinking," Andersen said.

"Even in the same person, 60 degrees in January is going to feel like summer — but in August, it's like freezing," she said. "When it was 56 degrees up here two weeks ago after our freezing polar vortex, I went to work without a jacket."

Mental perceptions trump physiological processes beneath the skin's surface that occur in Floridians, Andersen said. Small surface blood vessels constrict when exposed to cold, and they dilate in hot weather to release body heat.

"If you have been in a warm climate for a long time and return to a cold one, it might take a little longer for your circulation to adjust. But it's not for a long time. I mean, it's pretty quick," she said.

Andersen cited a personal example: In December, she visited Palm Beach County with a friend from Ecuador. She thought the ocean was warm; her friend found it freezing.

"To me, it feels comfortable and to her it's uncomfortable, even though our blood vessels may be reacting pretty similarly. It's our higher perceptions," she said.

A couple of cold-related facts, courtesy of the Harvard Medical School:

-- Taller people tend to get cold faster than shorter people. They have a larger surface area.

-- Fat's reputation as an insulating material is "well deserved."

But take note: The Harvard researchers were referring to subcutaneous fat layered under the skin — not the visceral "beer belly" fat.