Cold hands, warm heart

I've often wondered where this expression came from, so I looked it up.

Not showing one's feelings does not signify lack of feeling. For example, Dan rarely sends flowers or anything, but he's a case of cold hands, warm heart. Why a literally cold hand should indicate sympathy or affection is not really clear, but this expression has been so used since about 1900, and the Germans have an identical saying ( kalte Hand, warmes Herz).

(Taken from answers.com)