The salt and ice challenge is where you put salt on your hand or any other body part. Then, put ice on it and wait a few seconds for a burning sensation and a red mark. It is called a challenge because people often try it as a group. Whoever leaves the ice on the salt longest wins the challenge.
The "salt and ice" challenge is where you put salt on a body part and put ice on top and apply pressure for a certain amount of time. This causes a burning sensation. It is an extremely dangerous challenge to attempt due to the ice (Which quickly melts into water) now having a much lower freezing point, which is called a saline solution. This challenge CAN cause 2nd degree cold burns (Also known as chilblains), which is a superficial freezing of the skin, without penetrating into the epidermis, which generally results in blistering. It can, if held for long enough, cause frostbite (3rd degree cold burn), which is complete tissue destruction; Everything from the skin to the nerves are frozen and destroyed.
According to the game, the winner is whoever can hold the ice long enough. However in reality, the person who opts to not attempt this challenge is the true winner and the one without a possible hospital bill and missing limbs.