So he created a group on Meetup.com in early December and asked others to join. Now about 15 people meet every Sunday. They also have a ritual. “This guy brings music, like this tribal drum music, to energize us,” Mr. Kerkhoff said. “It’s the social, fun thing I do in the winter now.”
Many groups have adopted their own unique methods of getting into the water.
Sunday Swim, a group that started a year ago and meets every Sunday afternoon at Robert Moses State Park on Long Island, has a tradition of charging everyone into the water as a group.
“You step out of that water and you feel like an animal,” said Brendan Cook, 23, one of the group’s founders. “We really tap into our inner warrior.” Hundreds of people show up each week, ranging from teenagers to swimmers in their 60s and 70s.
Mr. To control his anger, Cook started diving into the ice. “I didn’t have an outlet for my stress, and I was having difficulty controlling my emotions,” he said. “Cold water has taught me to control chaos, to harness my inner energy. I feel more in control. I don’t get into arguments anymore.”
Other cold water swimmers, however, are meeting more informally in ad hoc setups.
Paul Dobrynin, the 39-year-old founder of a flooring company, takes a cold plunge on the roof of his building on Manhattan’s west side. “In the beginning I had this cheap, small, plastic blowup pool that I used to put ice in,” he said. “In November I received a 100-gallon tank made of rubber, which is used on farms for livestock to drink.”
“I run a hose through my kitchen, my bedroom, my bed, out the window, out the ceiling, for a cool dip,” he laughs. “It’s funny.”