Authorities at Yellowstone National Park are urging visitors to stay on designated boardwalks and trails surrounding thermal zones following an incident on Monday in which a teenager sustained “significant thermal burns.”

The 17-year-old was traversing the thermal region near Lone Star Geyser, close to the famed Old Faithful, when his foot “broke through the thin crust,” according to park rangers.

He was subsequently transported to a local hospital, suffering burns to his foot and ankle, as stated in a press release from the park, which is now investigating the event.

This marks the first reported thermal injury in Yellowstone this year, and the first in roughly 10 months.

Last September, a 60-year-old woman from New Hampshire also fell through the thin crust of a thermal zone, plunging into extremely hot water and injuring her leg. She had been walking off-trail with her leashed dog and husband, according to Nexstar’s KTVX.

Park rangers explain that the trails and boardwalks are designed to safeguard both visitors — who risk “severe or fatal burns” due to the scalding water beneath the “thin and fragile crust surrounding the hot springs” — and the “sensitive thermal features.”

Officials highlighted on Tuesday that more than 20 individuals have died from burns after entering or accidentally falling into Yellowstone’s hot springs. Swimming or soaking in these springs is strictly forbidden, and pets are not permitted in thermal zones.

This isn’t the first person to be injured at Yellowstone this year.

In May, a Florida man was gored by a bison. The same happened to a New Jersey man in June. In both cases, rangers say the men got too close to the animals.

Last summer, two people were reported to have been injured by bison in Yellowstone. There was only one reported in 2023.

The latter incident had a relatively happy ending, though. While the Arizona woman suffered fractured vertebrae and collapsed lungs after being gored, she later said “yes” to her boyfriend’s proposal at the hospital.

Also last summer, an Idaho man suffered minor injuries and was arrested on alcohol-related charges after allegedly kicking a bison at Yellowstone.