(CNN) -- The Polar Bear Plunge is not an event for the coldhearted. Participants actually pay up to jump into freezing-cold water, with the proceeds benefiting Special Olympics.
Last year, the various Polar Bear Plunges held by each state raised a collective $16 million.
"Each event is so much more than just a Plunge, with hot tubs and huge heated tents, bands, vendors, costume contests, DJs and more," said Bronwyn Schaefer Pope, vice president of marketing and communications for Special Olympics Minnesota. The events "allow people of all ages and abilities to do something wild and crazy to shake off the winter blues."
Be it a lake, an ocean or a river, plungers continue to jump. CNN looks at the five biggest Plunges in the United States:
Maryland -- January 29, 2011
Unlike many of the other Polar Bear Plunges in the United States, Maryland holds one massive event instead of multiple smaller ones.
"We determined that we would invest our time and energy into one event and maximize the craziness of that one event," said Tom Schniedwind, executive vice president for sports marketing for Special Olympics Maryland.
He says that Maryland's Plunge, which takes place in Chesapeake Bay, has five giant festival tents on the day of the event, including an extreme sports tent and a music tent.
"It's kind of a bucket list thing for our plungers, whether they're veteran plungers or first-timers," Schniedwind said.
Wisconsin -- February 5, 2011-March 5, 2011
Plungers can choose from a dozen different Polar Bear Plunge locations and a variety of dates. However, the Madison Plunge, which takes place on February 19, and the Oshkosh Plunge, which also takes place on February 19, are the largest.
"In Madison, you walk out onto the ice, turn around and face the crowd, and jump into a 20-by-20-foot hole that's cut in the ice," said Kelly Kloepping, vice president of communications for Special Olympics Wisconsin. At other locations, you might jump off of a dock or run off the beach into the water.
Minnesota -- January 29, 2011-March 12, 2011
What started in 1998 with 65 plungers has grown into a massive fundraising effort, including 14 different plunge locations. Last year, the Minneapolis location alone had 1,800 plungers and raised more than $320,000.
"Each site has unique aspects which build on the character of the local community," Schaefer Pope said. In Rochester, Super Plungers can jump 24 times in 24 hours. In Minneapolis, those too chicken to plunge can run a 5K.
"The Plunges in Minnesota are not for the faint of heart and can definitely be considered an extreme sport," Schaefer Pope said. "But they are also accessible to people of all ages and abilities."
New Jersey -- November 27, 2010-February 26, 2011
In New Jersey, Polar Bear Plunge participants can take a dip in the frigid Atlantic Ocean at two different locations. The Seaside Heights Plunge is the largest, with more than 4,500 plungers.
"They know exactly why they are jumping into the 30-degree water: for the athletes," said Doreen Pustizzi, senior director of communications for Special Olympics New Jersey.
Last year's event at Seaside Heights had more plungers than ever, despite being postponed a week because of bad weather.
Illinois -- February 25, 2011-March 19, 2011
More than 10,000 people attended the various Plunges in Illinois in 2010, and with 18 locations in 2011, Special Olympics Illinois is expecting plenty of participants.
"We strive to have a consistent, quality experience at all of our plunge locations around the state," said Michele Henson, director of communications and publications for Special Olympics Illinois.