An Auckland skin expert says young people taking part in the "frosty challenge" risk being scarred for life.
Young people taking part in the frosty challenge spray aerosol to the skin at close range for as long as possible, and compete with each other to see who can endure it the longest.
Auckland Skin and Cancer Foundation consultant Chin-Yun Lin described the challenge as a "silly craze", adding the use of any aerosol products in close proximity to the skin for a prolonged period can lead to permanent damage or disfigurement.
"There's a risk of ice burn, which is very similar to heat burn, and the longer you spray, the deeper the skin will freeze and the deeper the wound," Lin said.
"When you reach an equivalent to a third-degree burn, which goes through the dermis and affect deeper tissues, that would lead to permanent scarring and quite a lot of disfiguration."