CHICAGO (CBS) — About 50 hearty souls started the first day of the New Year with a plunge into the frigid water of Lake Michigan.

WBBM Newsradio’s Mike Krauser reports the air temperature was a bitter 18 degrees, and the water wasn’t much better at 37 degrees – nice day for a swim at North Avenue Beach, right? That’s what the dozens of people taking the Polar Plunge thought.

There’s a good reason for doing it, too.

“We do it for the Illinois Koala Bears,” said Brian “Big Cat” MaDougall, who started the tradition 13 years ago.

After taking the plunge, one swimmer said, “I can’t feel anything, it’s like a thousand knives in my body.”

Another swimmer said, “It was great. A great way to start the year.”

Some swimmers lingered in the cold water, but most were in and out and back to a warm car as quickly as possible.

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