Are they nuts? Dive into the water at 8 degrees Celsius (46 F)! Perhaps they are, but people are known to do strange things. Polar bear “swimming” or “plunge” is a tradition that dates back more than 100 years. It stems from the Scandinavian tradition of saunas as a way to cool quickly after the heat of the sauna. In China and Russia, winter swimming is said to be good for your health, and it is done not only on New Year’s Day but also as needed. Russian ice swimmers are called “walruses” rather than “polar bears” in North America. In North America, the oldest annual plunge belongs to Boston, Massachusetts (1904). The water temperature in Dorchester Bay on January 1, 2012 was 3 degrees Celsius (37 F), just above freezing. Anyway, over 600 swimmers came out to drink water. Complete submersion is the purist’s purpose. It is said that it is not so bad if you get your head wet. do not know! Costumes are optional, but preferred in ...