Two men have been issued summons after National Park Service officials said they walked up to the edge of Old Faithful.

The men, whose names have not been released, stepped off the boardwalk that keeps tourists a safe distance from the geyser and looked directly into the hole in the Earth, NBC News reported.

One man used his cellphone to take a close-up photo of the spout on Tuesday, ABC News reported.

The men now face a summons for thermal trespassing and are scheduled to appear in court in December, according to NBC News.

"Thermal area safety is an extremely important part of any trip to Yellowstone," officials said in a statement, NBC News reported.

Water shoots into the air at Old Faithful at 200 degrees, ABC News reported.

But steam can reach higher than 350 degrees.

Several people have been cited for walking onto the geyser over the years, The Associated Press reported. Others were burned when they fell or stepped on the thermal features of Yellowstone.