The NPS recommends avoiding hiking the Grand Canyon's inner trails between 10 a.m. and 4 p.m., when temperatures are at their peak. Temperatures in the inner canyon can reach over 120 degrees Fahrenheit in the shade, creating "extremely hazardous conditions for hikers," the NPS said.

A hiker has died on the South Kaibab Trail in the Grand Canyon National Park while attempting to reach the Colorado River.

A 67-year-old Texas man died Tuesday at the Grand Canyon after abandoning an attempt to hike down to the Colorado River. He turned around and began ascending toward the rim before he was found,

A 67-year-old man hiking in the Grand Canyon National Park died on a trail while hiking in extreme heat, which possibly caused hazardous conditions. The Grand Canyon National Park Service said that at about 11:50 a.m. on Tuesday, July 8, the Grand Canyon Regional Communications Center received a report of an unresponsive hiker.

Hiker dies in Grand Canyon as park warns of dangerous temperatures - The National Parks Service warns daytime temperatures at the Grand Canyon can top 120°F, ‘significantly increasing the risk of heat

A 67-year-old Texan planning to spend a night at Phantom Ranch on the floor of Grand Canyon National Park collapsed and died while hiking down the South Kaibab Trail.