Vince Vaughn and Lady Gaga made the plunge into the icy waters of Lake Michigan for a fundraiser for Special Olympics.
The celebs were joined by more than 4,500 other participants.
Vaughn, a Chicago-area native was dressed in his Chicago Blackhawks jersey and jeans. He first went in up to his knees, then eased himself down backward in the water. According to Chicago TV station WBBM, Vaughn described the event as 'fantastic' after coming out of the water. Vaughn was the guest of honor at the event, Lady Gaga's appearance was a surprise.
Gaga recently announced her engagement to "Chicago Fire" actor Taylor Kinney. Photos from the plunge show her and a shirtless Kinney going into the water for the 15th annual event.
This year more than 4,500 plungers raised more than $1 million. Last year, Tonight Show host Jimmy Fallon helped raise more than $1 million at the event. Fallon jumped into Lake Michigan wearing a suit and tie.