polar bear plunges

Koyamamotoくんのfollow-upです。こちらの方は寒中水泳が本当に体に良いことなのかに関する記事です。今日はなんだかbearが多いな。（UG）
http://d.hatena.ne.jp/A30/20130115/1358251782

Are polar bear plunges good for you?

The Coney Island Polar Bear Club, which claims to be the oldest "winter bathing" organization in the United States, was founded in 1903 by publisher Bernarr MacFadden, who believed swimming in the ocean in the wintertime was "a boon to one's stamina, virility and immunity."

Doctors, however, aren't so convinced that these plunges are good for you, noting that there is no solid evidence of any physical health benefits associated with swimming in freezing cold water. In fact, they say, the sudden drop in temperature can be dangerous for people with underlying health issues.

http://edition.cnn.com/2013/01/17/health/polar-bear-plunges/index.html?iid=article_sidebar