On the other side of the tent, though, Bernhard Hauser, 40, of Burghausen, was hunched over, eyes peeking out from a stack of blankets, offering monosyllabic utterances through clattering teeth as three paramedics kept close watch. The difference between the two men was remarkable. Hauser had finished 27:55.46, ahead of Koitka, but his body had a much stronger reaction to the cold.
When asked how this could be, Koitka deadpanned that he produced his own natural neoprene, the synthetic rubber used in wet suits. “It’s beer-o-prene,” said Koitka, 38, slapping and jiggling the flab on the midsection of his 243-pound frame.
Hauser, still shivering, eventually walked under his own power to the sauna. Later, he said he was surprised at the hubbub around him. He said he mostly felt fine — just cold. “I know my body and my physical constitution very well, and I am not a kamikaze swimmer,” he said, conceding that he could have used more training time.
Officials must be extra careful at these swims. They pay close attention to swimmers’ split times, monitoring signs of fatigue. Paramedics do not hesitate to pull someone from the water. The observation does not stop back on land: Swimmers’ bodies continue to cool after emerging from water, and swimmers sometimes reach their coldest body temperatures 30 minutes to an hour after they are done.
Swimmers have to monitor themselves vigilantly, too: their breathing, physical and mental states, and skin tone. “Hot pink is good,” said Jaimie Monahan, a top marathon swimmer from New York, who has taken to ice water swimming in the past few years. “Light blue, pale, that’s not good.”
Monahan, 37, completed an Ice Mile this past May in Reykjavík, Iceland, in 35 minutes in 37-degree water, entering a record book full of eye-popping figures. Last February, two men in Ireland, swimming in 40 degrees, lasted 2.05 miles in 57:45 and 2.06 miles in 54:49. In December 2012, a pair of men in Russia each spent over an hour in 32.5-degree water swimming more than 1.3 miles.
The first question ice swimmers receive, then, is why.
As in many extreme sports, participants embrace the opportunity to learn about themselves. You may catch a surprising glimpse of some unfamiliar corner of your psyche. For a fleeting moment, you may experience the intoxicating feeling of defying your fundamental instincts. The pleasure of doing it seems to pale in comparison to the feeling of having done it.
“I’m being honest, when it’s over, the euphoria is incredible,” said Rena Demeo, who finished an Ice Mile two years ago in Boston.
For others, it has everything to do with the joy of competition.
On Saturday at the Wöhrsee, in the shadow of Burghausen Castle (of some renown as one of the world’s longest castles), a D.J. spun tunes — “Ice Ice Baby,” of course — as the events unfurled. Students selling baked goods behind a foldout table paused to swim short relays. The sauna at times seemed as packed as a rush-hour train car.
Ten minutes after winning her first race, Wittig dunked herself in the wood-fire hot tub behind the pier. Her shivering was so pronounced that she struggled to raise a cup of tea steadily to her lips. But by then she was smiling and laughing. After racing in her youth, she had spent 15 years out of competition. Now here she was, thriving in a different, quirkier sport. She talked about breaking the 13-minute barrier in the 1,000-meter race next month.
Wittig did four more races, four more plunges into the ice water, before the afternoon was done.