A man has suffered severe burns after falling into a hot spring at Yellowstone National Park in the US state of Wyoming, park officials say.
Gervais Dylan Gatete, 21, of Raleigh, North Carolina, was with seven other people when the incident happened.
Just before midnight on Tuesday the group flagged down park rangers who helped transport Mr Gatete to hospital.
This is the first incident near the famous hot springs this year. Last June a man died after falling into a spring.
Mr Gatete, who is a hotel employee in the park, was flown from the airport in West Yellowstone to Salt Lake City, where he is in stable condition in hospital.
Yellowstone Superintendent Dan Wenk said in a statement that the park’s thermal features are dangerous, and the ground nearby is fragile and thin, with scalding water just beneath the surface.
“We continually stress that people must stay on trails and boardwalks in geyser basins, not only to protect resources, but for their own safety,” he said.
Some Yellowstone hot spring temperatures can reach up to 199F degrees (93C).
In 2016, a 23-year-old man died in the Lower Geyser Basin after leaving the boardwalk trail with his sister.
Authorities later determined it was too unsafe to recover his body, which had dissolved almost entirely by the following day.
The area of the park where the hot springs and geysers – which spout water into the air – are located is on the edge of the famous Yellowstone caldera, a “supervolcano” or “hotspot”.
The caldera’s activity fuels the thermal pools in the area.