The Chicago Polar Bear plunge is this Saturday January 25th at Oak St beach. Not to be confused with the Chicago Polar Plunge, which takes place in March, this frigid tradition is organized by the Chicago Polar Bear Club and challenges participants to take a dip in Lake Michigan to raise money for local families in need. No matter how much time you spend on the beach during the summer, you're probably not going to be prepared for just how cold the lake gets in January, so make sure that you bring something warm to wear!