At English Bay in Canada, maybe the birthplace of the Polar Bear Plunge, the air on New Year's Day was freezing and sleeting, and the water was nearly ice.

At Sullivan's Island, it only felt like it.

On one of the coldest days in the 15 years of this Lowcountry swim, one of its biggest mobs ever screamed into the surf in bathrobes, boas, bikinis and assorted regalia.

Bill Dunleavy, the owner of the pub that puts together the annual insanity, guessed that 2,000 people or more took the frigid plunge.

"And I was worried this morning because it was cold," the tuxedoed Dunleavy said with a shrug and a grin.

Across the jetties at Folly Beach, a third annual plunge drew as large a crowd as that swim has seen. "It was an awfully large turnout," said Mike Kirages of Snapper Jack's, who organizes the event.

Since a few hard partying madmen in permafrosted places got the plunge going nearly a century ago, the annual revel has become one of those I'll-do-it-if-you'll-do-it dares just about anywhere in the world.

On Sullivan's Island it raises money for Special Olympics. Dunleavy predicted this year's dousing would raise as much as $25,000. The Folly Beach plunge collects food and raises money for the Lowcountry Food Bank.

For the record, the water temperature was in the 50s and the wind chill down around 34 degrees.

As cold as the half-disrobed partyers were beforehand, swarming the streets around Dunleavy's Pub, they gasped as the wind smacked them as they hit the dunes.

They hopped barefoot across the beach like the sand was hot, jumping up and down in place along the starting ribbon.

Mary Ashley, 16, of Mount Pleasant, wasn't sure she wanted to take the plunge for her first time, not the way she huddled her arms around her slip of a princess gown and shivered.

"She has to do it. It's custom. It's tradition," said Ryan Bogdon, 17, of Mount Pleasant. And after all, he wore a crown.

"I'm cold," she said miserably.

Chris Langston of Mount Pleasant and his friend Chris DeJesus, of San Diego, wore butterfly wings — dragon wings, they insisted. The other guys in the Skeeter Club just laughed. Langston's wife, Maureen, made them do it, DeJesus said.

"She told me if I didn't she was going to ruin my life, and I said, 'I love you,' " Langston said with a wry grimace. "You know how that is."

Then the bagpipers marched up and the countdown started; when it hit 10 the mob broke for the Altantic Ocean, en masse, popped into the foam — and popped right back up like corks.

Ashley still had her arms around herself, her hair dripping wet. Her lips had turned blue. How was it?

"Good," she chattered. "Good."