Videos on YouTube are revealing a disturbing trend: the so-called fire challenge. Teenagers are setting themselves on fire and posting the video as a social media stunt.
The trend 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, 16, 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.
"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.