"Alcohol makes you lose heat much more quickly and makes it harder to regain heat afterwards, so don't drink until you come out of the water and rewarm, " says Traill.

CNN: Are polar bear plunges good for you?

Their ability to regain access to market financing in 2013 as planned (with Ireland dipping its toes into the water later this year) is far from sure.

ECONOMIST: The threat of a Greek exit: Unhappy in their own ways | The