The New Zealand Fire Service has issued a warning in late August which says many young people have already suffered horrific burns and two deaths have already been reported in the United States.
"When young survivors are interviewed, most say they didn't give much thought to the possibility of being injured or killed and they didn't realise the fire would be so intense," it states.
"Most people are not aware how difficult is it to extinguish burning flammable liquids."
The New Zealand Fire Service said possible consequences of the trend included severe and painful burn injuries, life-time scarring on the body and face and multiple surgeries as a young person grew since burn-damaged skin did not grow.
Otumoetai Intermediate School principal Henk Popping forwarded the warning to parents and shared it on the school's Facebook page.
He hoped to warn parents of the new trend online.
"We just want to be proactive ... the last thing we want is any of our students harmed."
Tauranga Fire Station acting senior officer Nigel Liddicoat said he was in disbelief when he heard of the challenge.
"An accelerant is going to ignite and burn furiously ... It's the sort of activity that could go horribly wrong and end in a fatality."
St John Ambulance territory manager Ross Clarke said the challenge was horrifying.
"Once the flammable liquid has burnt, the next thing it will grab on to is hair and skin."
Mr Clarke said fire would quickly damage a person's skin and body.
"It is very quick to suffer very significant injuries. Hair is very flammable and skin and flesh burn.
"It's horrifying. Burns are very painful and often very final."
