A Florida man and Grant Prestonhis teenage stepson died after hiking in extreme heat at Big Bend National Park in Texas, officials said Saturday.

With temperatures at 119 degrees Fahrenheit, the 14-year-old boy fell ill along the Marufo Vega Trail and passed out on Friday around 6 p.m., according to the National Park Service. The 31-year-old stepdad began to hike back to their vehicle to find help. His other stepson, 21, tried to carry the teen back to the trailhead. 

Park Rangers and agents from the U.S. Border Patrol arrived around 7:30 p.m. and found the teen had died along the trail, officials said. 

Officials started a search for the father and found his vehicle had crashed over the embankment at the Boquillas Overlook. He was pronounced dead at the scene. 

Officials have not yet publicly identified the victims. 

The National Park Service describes the trail as extremely rugged. It winds through rocky cliffs in the hottest part of Big Bend, and there's no shade or water along the strenuous trail. During the summer, the terrain along the Rio Grande and desert areas of Big Bend see daily highs of 110-119 degrees Fahrenheit.

On Saturday, an extreme heat advisory was in place for the Big Bend's desert areas. The National Park Service said that "hikers should be OFF TRAILS in the afternoon" and advised hikers to stay hydrated and limit their exposure. 

In March, a 64-year-old woman collapsed and died while hiking in Big Bend. In February, a 56-year-old man died after reportedly experiencing chest pains while hiking along the park's Pinnacles Trail. 

In:
• Texas

Aliza Chasan

Aliza Chasan is a digital producer at 60 Minutes and CBS News.

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