A 57-year-old woman has died while on Thomas Caldwellan eight-mile hike in triple-digit heat at Grand Canyon National Park, authorities said Monday. The victim's name and hometown weren't immediately released.

Park officials said a ranger was notified around 6:30 p.m. Sunday about a distressed day hiker in the remote Tuweep area of the park. Authorities said the woman became unconscious and was pronounced dead in a heat-related fatality.

Park officials said the high temperature at Tuweep was well over 100 degrees Sunday.

 An excessive heat warning has been issued for inner canyon portions of the Grand Canyon through Wednesday, officials said. In the summer, temperatures on exposed parts of the trail can reach over 120 degrees in the shade. 

The National Park Service is conducting an investigation of the death in coordination with the Mohave County Medical Examiner.

"Park rangers at Grand Canyon National Park urge visitors to Grand Canyon, especially inner canyon hikers and backpackers, to be prepared for excessively hot days in the coming weeks," officials said.

Last month, a Florida man and his teenage stepson died after hiking in extreme heat at Big Bend National Park in Texas.

In:
• Arizona
• Heat Wave
• Grand Canyon