cold hands, warm heart

A cold hand and a warm heart.
[1903 V. S. Lean Collectanea III. 380]

I did take her hand. ‥Cold hand, warm heart!
[1910 W. G. Collingwood Dutch Agnes 206]

I knew you would be on my side. ‥Cold hand—warm heart. That is the saying, isn't it?
[1927 J. M. Barrie Shall We join Ladies in Plays (1928) 840]

A hot, humid night, but her hands cold. Cold hands, warm heart.
[1962 E. Linington Knave of Hearts xv.]

‘Belle, your hands are cold,’ he said. ‘Cold hands, that's funny?’ ‘You know the old saying, “cold hands, warm heart”.’
[1985 D. & S. Rosen Death & Blintzes xxvi.]

Related to: love

Bibliography of major proverb collections and works cited from modern editions is available here.

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).