It was a Polar Plunge for the history books, in more ways than one.
PHOTOS: 15th Annual Chicago Polar Plunge
Not only did a record number of plungers jump into the freezing lake Michigan water, but some big name celebrities showed up, some without warning.
Wearing a Chicago Fire Department t-shirt, pop star Lady Gaga took the polar plunge. She was dropped in the freezing 32-degree Lake Michigan water while on the shoulders of her fiance Taylor Kinney.
Moments before, complete with a live bag pipe performance, Chicago area native Vince Vaughn took the plunge wearing a Chicago Blackhawks sweater. Vaughn said the courage and dedication of the athletes in the Special Olympics is what led to his decision to participate in the Polar Plunge. His new comedy, "Unfinished Business," is out on March 6.
Some area politicians showed up, including State's Attorney Anita Alvarez and mayoral candidate Jesus "Chuy" Garcia.
The Polar Plunge involves brave souls going into Lake Michigan, despite the freezing temperatures inside the water, and below freezing outside.
"It was cold, I'm not going to lie, but it was fun," said Tammy Jenson.
Proceeds raised provide year-round activities and events to nearly 5,000 athletes with special needs.
"We know Chicago is a city of heart you could feel that heart pounding today," said Special Olympics Chicago President Casey Hogan.
With such a great turnout, organizers are excited for what next year could bring.
The plunge raised more than $1 million for Special Olympics Chicago, which provides year-round activities and events to nearly 5,000 athletes with special needs.