No way
did you hear about the masochist that liked a cold shower? he took a warm one instead!
I do this. How long for generally depends on how strong I'm feeling that morning - it can be a bit token if I'm feeling weak. But good to wake you up, and I think the psychological benefit is important: forcing yourself to do something you know is going to be pretty unpleasant to start with.
Funnily enough, I tend to do it less in the summer. Possibly the light mornings already wake me up enough. It makes a kind of sense though, in that, I think, a brief cold shower will (counter-intuitively) warm you up since it's not enough to actually lower your core temperature, but will tell your body that it's cold and trigger its heat-retention mechanisms, contracting blood vessels, etc.
