When salt is mixed with ice on top of human skin, a reaction occurs which burns the skin in a way similar to frostbite, potentially creating second- or third-degree burns (if not permanent nerve damage) within seconds.
Yet, that's what a group of teenagers were doing to themselves at a recent sleepover on Queensland's Sunshine Coast, much to their parents' horror.
Termed the salt and ice challenge, the dangerous stunt is the new way for teens to make fools - and physically injured fools, at that - of themselves on social media.
The Sunshine Coast Daily reports:
Rebecca Etherington's 14-year-old daughter, Hannah, will have a permanent scar on her leg as a painful reminder of what she thought was "harmless fun".
Mrs Etherington had never heard of the "salt and ice challenge" until she saw the open wound on Hannah's leg last week.
Hannah told her she had been at a sleepover with a friend and they had taken part in the challenge, which involves pouring salt on the skin and then pressing an ice cube to the area.
The "challenge" first made headlines in the U.S. back in 2012, but it appears it may have made its way to Australia.
Hannah's mother went on to explain that her daughter and her friends discovered the challenge "on social media".
Searching "salt and ice challenge" on YouTube returns 233,000 results. Some of the most-watched videos include "DEADLY ICE BUCKET CHALLENGE" and "Kid Dies From Salt & Ice Challenge (Almost)".
It's not the first time a dangerous challenge has been spread across social media. Two years ago, parents were concerned about the cinnamon challenge, in which teens (and adults) attempted to eat a tablespoon of dry cinnamon without gagging.
When the cinnamon challenge didn't go as planned, the cinnamon could find itself up the nose of the person trying to consume it, which created a strong burning sensation. There was also the possibility that the cinnamon would be inhaled, becoming lodged in the lungs, potentially causing pnuemonia.
But the salt and ice challenge is a different kettle of fish, because injuring yourself isn't what happens when things go wrong, it's actually the whole point of the exercise.
Mrs Etherington told the Sunshine Coast Daily that, while many families would see such behaviour as a cry for help, the challenge divorces self-harm from emotional turmoil.
"They've turned what used to be something done by kids who are emotionally damaged into the latest craze."
Have you heard about the Salt and Ice Challenge? Tell us your stories in the comments.