A 17-year-old male suffered significant thermal burns to his foot and ankle area Monday while hiking in the vicinity of Lone Star Geyser near Old Faithful.

The unidentified juvenile’s foot broke through the thin crust in the geyser basin. Emergency medical staff responded and transported the patient to a hospital for further treatment. Park officials have yet to say if the hiker was off trail or in a protected area.

“Boardwalks and trails protect you and delicate thermal formations. Water in hot springs can cause severe or fatal burns, and scalding water underlies most of the thin, breakable crust around hot springs,” said the Public Affairs Office in a Tuesday press release, adding, “This incident is under investigation and there is no additional information to share.”

The park’s hydrothermal system is the visible expression of the immense Yellowstone volcano, according to park reports. Heat from the volcano is transferred to the groundwater, which makes makes its way to the surface as a hydrothermal feature.

Thermal basins are areas where several hydrothermal features are found. Sometimes features are connected, exhibiting distinct behavior based on the activity of a connected feature.

There are four main types of hydrothermal features in Yellowstone: hot springs, mudpots, fumaroles and geysers. There are also travertine terraces, which form where the water of hot springs travel through limestone bedrock.

Topping the list of geologic wonders are hydrothermal features: hot springs, mudpots, fumaroles, and geysers. Well over 10,000 different hydrothermal features have been estimated to be active within the park.

Even more incredible might be that over half of the world’s active geysers are found in Yellowstone. Every year, some 500-700 geysers are active. In 2011, it was determined that 1,283 geysers have been recorded as erupting in Yellowstone. This is truly incredible, when all of the rest of the world’s geysers combined number less than 500.

Hydrothermal features are extremely dynamic, changing throughout the day, across seasons, and over the years. This makes revisiting the different thermal basins so interesting. Besides seeing familiar sites, you can also see how those areas have changed since the last visit.

Although it is a common assumption that animals cause numerous wounds and deaths in Yellowstone, hot springs actually account for more injuries and fatalities. And it isn’t close, according to a U.S. Geological Survey report.

Over the history of the national park, dating back to 1872, two people have been killed as a result of bison encounters and eight from bear encounters (additional fatalities occurred outside the park boundaries). And over the past few decades, there have been an average of a few injuries per year due to human interactions with animals.

Yet, during the same time period, deaths related to hot springs are more than double those from bears and bison combined. Twenty two people have lost their lives due to scalding (one additional fatality occurred just north of the park boundary, at LaDuke Hot Spring), and there have been hundreds of injuries. The number of fatalities might be increased by one if the disappearance of a man who was staying at Fountain Hotel, in Lower Geyser Basin, is counted (it is presumed that he fell into a hot spring during a nighttime stroll because no evidence of his disappearance has ever been discovered).

The first reported hot-spring death was in 1890, while the most recent occurred three years ago, on July 31, 2022, when a 70-year-old California man died after he entered the Abyss hot springs pool at Yellowstone Lake’s West Thumb Geyser Basin.

In addition to burns, toxic gases may accumulate to dangerous levels in some hydrothermal areas. If you begin to feel sick while exploring one of Yellowstone National Park’s geyser basins, leave the area immediately.

This is the first known thermal injury in Yellowstone in 2025. The last reported incident occurred in September 2024, when a 60-year-old woman visiting Yellowstone National Park from Windsor, New Hampshire, reportedly suffered second and third-degree burns to her lower leg while walking in a thermal area near Mallard Lake Trailhead at Old Faithful.

The woman was walking off-trail with her husband and leashed dog in a thermal area when she broke through a thin crust over scalding water and suffered burns to her leg. The husband and dog were not injured.

Pets are not allowed on boardwalks.