The "salt and ice challenge" was popular on the internet a few years ago but it soon faded after people got serious burns. Unfortunately, the internet has a short memory and people are apparently up for this dangerous challenge again.
Prevention and parent groups want to stop this challenge from getting popular again. The 'game' is to combine salt and ice on your skin and see who can endure the pain the longest. The salt lowers the ice's temperature to 1.4 degrees Fahrenheit which can cause burns that are similar to frostbite.
Salt and ice are fairly easy for a child to get their hands on and the numbness and redness disguises the first degree burns that can happen. These burns can send it's victims to the hospital which is why these prevention groups are trying to educate parents and have them looking for these types of marks.