A 48-year-old man suffered severe burns at Yellowstone National Park after falling into a hot spring at the Old Faithful geyser.

Rangers were called to the Old Faithful Inn on Sunday after Cade Edmond Siemers, a U.S. citizen who resides in India, suffered severe burns to a significant portion of his body, the park service said. Siemers told rangers that he went for a walk without a flashlight and tripped and fell into the thermal water.

Rangers found evidence that Siemers may have been drinking alcohol at the time, according to the National Park Service.

Download the NBC News app for breaking news and politics

When they went back to the scene Monday, authorities found Siemers' shoe, hat, and a beer can along with footprints leading to and from the geyser.

The 48-year-old was taken to the Burn Center at Eastern Idaho Regional Medical Center.

"Investigations continue today, including assessing any damage to the geyser cone," the park service said Monday. "The results of the investigation will be forwarded to the United States Attorney’s Office for prosecutorial review."

Earlier in the month, two unidentified men were issued a summons for thermal trespassing after they were photographed at the edge of Old Faithful.

The tourists, one with a phone in his right hand and apparently taking an up-close-and-personal snapshot of Old Faithful, ignored signs that are prominent on trails throughout the park, a witness said.

They are set to appear in federal court in December, according to the National Parks Service.