Every year, hundreds of people take the plunge to raise money for Chicago's Special Olympics.
"Getting that site prepped for this takes a week," Michael Kelly, general superintendent of Chicago Park District, said. "Driving tent stakes doesn't happen overnight because the ground is frozen. So it's a big deal."
Frozen ground, and frozen water.
"You can't thank enough the volunteers and park district personnel who were out there removing 3 feet of ice this week and constantly breaking it up to get ready for Sunday," Kelly said.
Chicago Mayor Rahm Emanuel will participate in the Polar Plunge for the first time on Sunday.
"I made a bet to the children to the City of Chicago and I took a whooping," Emanuel said. The mayor promised to participate if Chicago children read two million books. He and former Chicago Bear Israel Idonije spoke about the event on Windy City LIVE.
"And Mayor, I know you wanted a recount of books read. We keep pretty fastidious records at the library. Kids read not only 2 million books, they read 2.1 million books," Liz McChesney, Chicago Public Library, said.
The lake will be 32 degrees. And the Polar Plunge helps Special Olympians like Keith Tyler.
"This is about winning the opportunity. It's not winning, it's not about losing. It's just giving all at once and giving everything all you got," Tyler said.
Special Olympics, which was founded in Chicago in 1969, supports programs year-round.
"We are at 3,000 plungers and are looking to breaking our fundraising records of $1 million," Jen Kramer, Special Olympics Chicago, said.