Boy, 14, dies hiking in 'extreme heat' of 48C before stepdad killed trying to save him

A man and his 14-year-old stepson have both died in a double tragedy while hiking in extreme heat.

The unnamed 31-year-old had been hiking the Marufo Vega Trail in Texas on Friday with his two stepsons from Florida amid scorching 119F (48C) temperatures when they ran into difficulty, according to the National Park Service.

They had been at Big Bend Park, a reserve on the US-Mexico border known for its difficult-to-reach rocky desert terrain.

Problems began when younger of the boys, aged 14, fell ill while on the hike and lost consciousness, leading the stepfather to hike back to his vehicle while the older 21-year-old tried to carry him to the head of the trail.

The unnamed 14-year-old became unconscious, leading his stepfather to go back to his vehicle to find help (stock) (Getty Images/iStockphoto)

Local authorities received the first reports about the emergency at about 6pm local time on Friday, and park rangers and U.S. Border Patrol agents arrived an hour-and-a-half later to find the 14-year-old had died.

A search for the father then turned up the wreckage of a vehicle at around 8pm, which had crashed over an embankment at the nearby Boquillas Overlook.

The man was pronounced dead at the scene. The tragedy came amid recent heatwave temperatures in West Texas, conditions which are magnified at desert parts of the Marufo Vega Trail with no shade or water.

A statement from the National Park Service confirmed the two deaths and warned hikers not to attempt the trail in extreme heat.

Authorities found the 14-year-old dead before the father's crashed vehicle was discovered at nearby Boquillas Canyon (stock) (Getty Images)

It read: "A team of Park Rangers and U.S. Border Patrol Agents reached the scene at approximately 7:30 pm and located the young victim deceased along the trail. A search was then initiated for the father.

"At approximately 8:00 pm, his vehicle was located crashed over the embankment at the Boquillas Overlook. The 31-year-old male was pronounced deceased at the scene of the crash.

"The Marufo Vega Trail winds through extremely rugged desert and rocky cliffs within the hottest part of Big Bend National Park. No shade or water makes this strenuous trail dangerous to attempt in the heat of summer.

"Big Bend is currently experiencing extreme heat with daily highs reaching 110-119 F at low elevations and along the Rio Grande."

The National Park Service added that the incident remains under investigation.