For the 150 members and 200 friends of the Coney Island Polar Bear Club, the sound of a conch shell is the call to plunge into the Atlantic Ocean. The club was founded in 1903 by New York’s “Father of Physical Culture” Bernarr Macfadden, who believed that an icy dip boosts stamina, immunity and virility (woof). The frigid weekly swims include jumping jacks to warm up and a circled-up chant of “polar bear, polar bear” followed by a freestyle swimming session. To prevent hypothermia, lifeguards limit immersion to ten minutes, and members often partake in hot showers and banya visits post-dip. Nonmembers can participate in one free guest swim per year in addition to the open swim on New Year’s Day (1pm; meet 11am at Boardwalk at Stillwell Ave, Coney Island, Brooklyn), although donations to campsunshine.org are encouraged. If you don’t want to leave your belongings unattended, bring a friend along to hold your things and take pictures. 917-533-3568, polarbearclub.org. Annual membership $35, guest swim free.