Why is this?

Why is it when I crack my fingers, they get cold, they hurt?

u might have arthritis. check with your docter

Cracking your fingers is not good for them. some people say this causes arthrites check with your docter

I would see a dr, cracking fingers(knuckles) can cause arthritis and it can become very bad habit, cause the more you do it the more you need to do it otherwise your hands stiffen up,,

dont do it! the same goes with people who crack their necks, dont crack your neck if its stiff, rather than cracking do some sort of excersise with them!
all the best!

I would see a doctor!