As extreme heat continues, Grand Canyon National Park says don't hike between 10 a.m. and 4 p.m.

By Kirsten Dorman
Published: Sunday, July 16, 2023 - 9:41am

Grand Canyon National Park Bright Angel Trail Victor Vomit heat illness warning sign
Grand Canyon National Park
A “Victor Vomit” sign warns hikers of the dangers of heat illness on the upper Bright Angel Trail at Grand Canyon National Park.

The ongoing stretch of heat enveloping Arizona means highs are expected to reach 119 degrees at Phantom Ranch inside the Grand Canyon.

Jeff Stebbins with Grand Canyon National Park said there’s a 20-degree difference between the canyon’s rim and the bottom, making it even more dangerous for hikers.

“People have this impression that heat rises,” Stebbins said, “but within geologic formation like the grand canyon there's something called adiabatic heating in which heat actually stays near the bottom.”

Stebbins said the park is advising people not to hike between 10 a.m. and 4 p.m. because of the heat.

Currently, there aren’t any restrictions on hiking. But Stebbins said there’s been talks of posting staff at points along the trail and to turn people back for their safety.

“They can still get the experience they’re looking for, hiking below the rim, but they’re not subjecting themselves to potentially fatal consequences,” Stebbins said.

So far this year, more than 300 people have been rescued and seven have died at the canyon. For those brave enough to venture out, there are QR codes with safety tips posted on the trailheads.

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