Teenagers are setting themselves on fire and posting the video as a social media stunt.
It has become so popular that a quick YouTube search for the term "fire challenge" turned up tens of thousands of videos.
In the videos, teens typically apply flammable liquid to their bodies, then flick a lighter. They quickly douse the flames before they can be hurt, but not everyone is quick enough.
Fernando Valencia did the challenge and ended up burning his waist and neck. Now he’s sounding the alarm, and has posted video of his burns as a warning.
Valencia, 16, told KABC News in Los Angeles that he couldn’t see through the flames on his body.
“You just see fire, you can’t really see nothing,” he said. “Since I saw other people fail, I thought I could do the same thing but actually last longer under the flame ... I can't really say nothing else besides it was a dumb idea.”
Similar attempts by other teens have resulted in emergency room visits all over the country, and authorities are urging parents to pay attention.
“We’re just asking parents and even other teenagers to sit down with each other and talk about what the real consequences are,” Micki Trost of the Colorado Division of Fire Prevention and Control told ABC News' Denver affiliate KMGH-TV.
The trauma of a stunt gone wrong can be more than physical. Some experts say teens can find it hard to rid their minds of the images of fire.
“It can create this feeling of risk that can be exciting in the moment, but then can also make some of the kids that we see have trouble with sleeping,” Brad Jackson, a child psychologist with the burn unit at Children’s Hospital Colorado, told KMGH., "They often become more fearful about other situations where they might be at high risk."