Why does warm water burn when your hands are really cold?

Answer 1

well say if your hands r warm and u put hot water on it at 80 c it will feel very very hot. so is 65 c difference roughly. so if u had really cold hands at 5 c and u put warm water on it, because your hand are changing temp so quickly it upsets your nerves in ur hands and it makes it feel so hot.
so if you are at 5 c and u put your hands in 48 c water it will feel like 80 c water being put on your hands.
the water is relatively 43 c higher then your body.

Answer 2

The reason that warm water burns your hands when they are cold is something called habituation. When your hands are continually exposed to cold, the nerves in the skin of your hands habituate ("get used to") to the cold temperature. The low temperature has become the norm. When your hands are then exposed to a high temperature, the difference between the habituated (low) temperature and the new (high) temperature is large enough to make it feel like a burning sensation.