Outside on the Coney Island boardwalk in Brooklyn, passersby tightened their scarves against the 35-degree late January weather. In contrast Ms. Frias-Colon was about to take a dip in the Atlantic Ocean’s 30-degree water.

The gap-toothed New Yorker isn’t insane. She is a member of the Coney Island Polar Bear Club, an organization of people who gather every Sunday between the months of October to March to go coldwater swimming.

Ms. Frias-Colon, 35, is also one of the few but steadily growing number of women who are joining the club. For more than 100 years, the Polar Bear Club’s members were middle-aged or retired men. Now 12 out of the 57

active members are women compared to fewer than a handful a year ago, and the club expects a growing number to come for the fun.

Louis Scarcella, the club’s president, attributes the rise to the club’s increased publicity, and overall membership growth.

“We do have more women who are trying to make it and get in their 12 swims,” Mr. Scarcella said, noting that to become a full member, a candidate needs to complete 12 cold water swims.

"We Like Having Women"

The guys don’t mind. In fact, the club is hoping more women join.

“We like having women,” said Oscar Abolafia, who described himself as sixty-something and has been cold water swimming for 14 years. “The women in many ways take to the water better. We would like to get more female members, I really think they add to this.”

Nevertheless, change won’t come overnight. At a recent club meeting, swimming trunks far outnumbered bikinis.

Ms. Frias-Colon started swimming in December, and said that she doesn’t know why more women haven’t joined.

“It’s definitely not a macho thing, they don’t treat us any differently,” she said of her male counterparts. “I feel at home here.”

The female polar bears are from diverse backgrounds; they include lawyers, bankers, schoolteachers, housewives, and even a handful of elderly Russian women; Ms. Frias-Colon is the assistant deputy to the New York City Commission of Education.

What the women do have in common is that most are athletes and are active in other physical activities.

Janelle Barabash, a member for three years is continuing a family tradition. Her great grandfather started coldwater swimming at the turn of the century, and she remembers watching her father every Sunday at Coney Island as a girl.

Montserrat Hernandez, 41, a sociologist, began coldwater swimming after witnessing the World Trade Center disaster on Sept. 11. She sees cold water swimming as a de-stressor. But her husband has yet to join, despite repeated invitations.

“Immediately people think that you’re crazy, you guys are nuts, but it’s such a spiritual experience for me,” she said. “You feel like you are leaving the world when you go into the water.”

Barabash speculated that women join the Polar Bear Club for the some of the same reasons that men join.

“I think we want to live the thrilling experience as well,” she said.

Stephanie Monseu, a 35-year-old circus performer, is on her seventh swim and hopes to be a Polar Bear soon. Monseu enjoys downhill skiing and is an avowed thrill seeker. Cold water swimming, she said, has also helped offset her seasonal depression.

“For me I’ve always sought out really extreme physical experiences,” said Ms. Monseu, who also appreciates the cameradie of the Polar Bears. “The moral support of knowing that a bunch of other kooks will be out there is a great motivation to get out there.”

But it’s not for everyone, she conceded.

“You can’t go in slowly, otherwise every nerve in your body screams no! The weirdest feeling is spinal fluid cooling down,” she said. “It feels like my body temperature is cooling and my spinal fluid feels like it’s turning into slush.”

"The Induction of A Polar Bear Girl"

For Ms. Frias-Colon being a Polar Bear is a dream come true. At her induction on this recent Sunday she and Louis Scarcella, the club’s president looped arms as they prepared for the icy dip.

Following club tradition, Mr. Scarcella launched the procession toward the boardwalk by blowing into a conch shell. The group of 40-plus people paraded onto the frozen tundra of ice and sand.

Heads turned, mouths dropped, and many onlookers gawked at the sight of a throng of people in bathing suits splashing happily in the water.

David Weinraub and his son Elias, 9, and a friend Ian Herrera, 9, stopped to watch the group splash and scream in the darkened waters.

“They’re crazy,” Ian said.

“I’d never do it,” Elias said.

And after a minute or so the boys observed that the human polar bears were emerging from the

water. “Look there’s fewer of them now,” Ian said.

Nevertheless, the adrenaline from the group was far from over. The club members were high-fiving and congratulating Ms. Frias-Colon who, as an official Polar Bear, was crowned with a white fur hat with the Polar Bear emblem.

“Crazy, that’s what I think,” said Ms. Frias-Colon’s husband who arrived after the swim to take pictures of his wife, the Polar Bear. “No, I would never do it.” Ms. Frias-Colon’s daughters Nairobi, 9, and Lida, 12, shook their heads with disapproval at their father. “My dad won’t do it,” said Nairobi. “But I will someday.”

“When I’m older I want to do it,” Lida, a soft-spoken girl said as she held onto a stuffed polar bear. “I want to be a polar bear, and see more girl polar bears”