Officials at New Trier High School are warning parents about a growing trend on social media that involves students jumping into cold lake waters as part of a game.
Referred to as the "cold-water challenge," it involves nominating a person to jump into the water or pay the price. Video of the jump is taken and posted online.
It was started with the intention to raise money for charities but has now turned into a big game.
Jackson Hamilton, a senior at New Trier, said he was nominated by a friend in Michigan.
"I don't think there really is a purpose," Hamilton said. "It's just kind of to be fun and most people say if you don't jump within 24 hours you have to get me something like Chipotle or buy me dinner one night."
"It was really cold," he said, "like where you can't breathe for a few seconds."
After teens in other areas around the country have suffered ankle injuries, stitches or worse during their jumps, New Trier school officials tell parents the trend is potentially dangerous.
"While this may seem like harmless fun, we believe it is a safety concern," a letter from the school to parents reads. "A few students already have been injured while jumping into shallow water from rocky shorelines."
In Carver County Minnesota, 16-year-old Davis Colley drowned after jumping into Eagle Lake. While students have told local media he jumped as part of the challenge, the Carver County Sheriff's Office told NBC 5 that detectives have not determined whether it was related and continue to investigate the death.
Detectives also point out Colley went into the water alone and without anyone filming.
New Trier officials said they discovered this week that several students have participated in the game in which they challenge each other to jump into Lake Michigan. A couple students were injured while jumping into shallow water from rocky shorelines.
Though the challenge has taken place off school property, the letter suggests parents discuss the game with their children.
"The lake is a dangerous place," school spokeswoman Niki Dizon said, "especially when there are no lifeguards on duty and the beaches are closed "
Dizon said the school wants students to make wise choices and not feel pressure to take the challenege.