A 60-year-old woman from New Hampshire was seriously injured while walking in a thermal area at the Yellowstone National Park in Wyoming.

The woman was walking off-trail with her husband and leashed dog in a thermal area near Mallard Lake Trailhead at Old Faithful on Monday when she "broke through a thin crust over scalding water" and suffered second and third-degree burns to her lower leg, the National Park Service said in a news release. Her husband and dog were not injured.

The couple went to a park medical center where they were evaluated and the woman was later transported to a hospital in Idaho for further treatment, the news release said.

The incident is the first known thermal injury in Yellowstone in 2024, the National Park Service said, adding it is under investigation.

Yellowstone explosion, explained:A dive into national park's recent thermal activity

NPS: Exercise extreme caution around hydrothermal areas

In the news release, the park service reminded visitors to "stay on boardwalks and trails in hydrothermal areas and exercise extreme caution."

"The ground in these areas is fragile and thin, and there is scalding water just below the surface," the news release said, adding pets are "prohibited on boardwalks, hiking trails, in the backcountry and in thermal areas."

Hydrothermal explosion at Yellowstone happened earlier this year

In July, Yellowstone National Park visitors were startled by an unexpectedly fierce hydrothermal explosion – an eruption of underground hot water – at Biscuit Basin, that spewed steam, boiling water, mud, and grapefruit-sized rocks hundreds of feet into the air.

No one was injured, but the July 23 explosion in the Biscuit Basin area, just 2 miles north of the famous Old Faithful geyser, damaged a boardwalk and nearby thermal pools. The park service has closed Biscuit Basin since as it assesses the area.

Saman Shafiq is a trending news reporter for USA TODAY. Reach her at [email protected] and follow her on X and Instagram @saman_shafiq7.