Nico,
I could never play piano with cold hands and fortunately I rarely had to. I think I have told this story here before, but in the icy snowy cold winter of 1963 I was playing a club deep in the heart of the New Forest and within a few weeks they couldn't afford to heat the place. It got so bad that eventually we were playing in our overcoats, but that doesn't keep your hands warm. My sympathies and enough to put you off playing for life - at least I was getting paid for it!
John,
Yes, we dabbled with coke and once you got it going it was OK.
Maurice