An article in the BostonHerald.com earlier this year (16/2/09) talked about a craze hitting the UK – Cryotherapy.

People for years have plunged into freezing waters around the world to celebrate one event or another.  Now it is possible to expose yourself to the 166 degrees below zero conditions by passing through a specially designed chamber.
The Boston Herald reports that “The English operators limit customers to three minutes in the minus-166 chamber after passing through two others at plus 14 and minus 76 (you could call them warm-up rooms, pardon the expression) clad in a bathing suit and special shoes.”
An account in the London Telegraph said that if you stay in for eight minutes you’ll be dead.
Devotees say “the massive hormone rush from the freezing temperatures can benefit anyone suffering from stress, burn-out, insomnia or depression,” and it reportedly helps psoriasis, arthritis, rheumatism and boosts athletic performance.
I have heard of exposure to sunlight helping psoriasis but this is a new one – and one I wouldn’t be so keen to try myself.