A woman died at the Grand Canyon National Park while trying to hike eight miles on Sunday, the National Park Service said.

The 57-year-old was hiking near the Tuweep area of the park when she became unconscious, according to a news release from the park service. A park ranger found her early Monday around 1 a.m. and she was pronounced dead.

The temperature in the area was over 100 degrees and reached nearly 114 degrees in some areas, according to the park service.

An excessive heat warning is in place for the inner parts of the Grand Canyon through Wednesday, NPS said.

Hikers are advised by park rangers to not hike the inner canyon between 10 a.m. and 4 p.m. during the summer months, as parts of the trail can reach over 120 degrees.

The park service is investigating the incident alongside the Mohave County Medical Examiner.

Heat-related deaths on the rise

The woman's death comes less than two weeks after a stepfather and one of his stepsons died after hiking in extreme heat in Big Bend National Park in southwest Texas, the park service said in June. Temperatures were as high as 119 degrees, according to the agency.

Heat-related deaths have climbed 74% since 1980, a 2021 study found. And extreme heat is the No. 1 weather-related killer for humans, according to the Environmental Protection Agency.

"What is most problematic about heat is that this is a sneaky climate issue because it kills many people, but it is not impressive like a hurricane or something. It's just happening all the time, so it is sneaky," environmental epidemiologist Tarik Benmarhnia of the University of California, San Diego told CNN.

More than 600 people in the United States are killed by extreme heat every year, according to the US Centers for Disease Control and Prevention.

In Mexico, at least 112 people have died as a result of "natural extreme temperatures" since March, according to the country's health secretariat.

As humans face hotter and hotter temperatures, officials are urging people to take safety precautions, including staying hydrated, avoiding leaving pets and kids in cars unattended and finding cool, indoor spaces to wait out the heat.