Are polar bear plunges good for you?

People run into the water for Coney Island Polar Bear Club's New Year's Day swim in 2013.

Story highlights

  • When people immerse themselves in frigid water, their bodies go into "cold shock"
  • Sudden temperature drops can be dangerous for people with underlying health issues

This story originally published on CNN.com in 2013.

(TIME.com)Vinny Guadagnino, the fist-pumping star of the MTV reality show "Jersey Shore," made a splash when he took a dip in the freezing cold waters of the Atlantic Ocean as part of the Coney Island Polar Bear Club's 110th New Year's Day Swim.

Guadagnino, who has done the plunge twice, told OK! magazine the experience was exhilarating.
    "You get a rush when you're there because there are so many people doing it," he said. "It's definitely like a shot of adrenaline ... It doesn't affect you that much -- you just have to go in, and do it, and jump back out... Afterward, as soon as I get out, I have a towel waiting for me, and I dry off quickly. That's it -- and then, I just chill."
    Okay, so Guadagnino was swimming for Cold-EEZE and was taking the plunge to raise money for charity, but there are plenty of others who take chilly dips for their health.
    The Coney Island Polar Bear Club, which claims to be the oldest "winter bathing" organization in the United States, was founded in 1903 by publisher Bernarr MacFadden, who believed swimming in the ocean in the winterti