Sarah Beadle died after becoming separated from her children and ran out of water

Sarah Beadle loved outdoor activities. Photo / Supplied via Facebook

By Anita Snow and Paul Davenport

The husband of a Texas doctor says she died at the bottom of the Grand Canyon after she ran out of water and grew dizzy from heat exhaustion on a hike with their daughter and a nephew.

Scott Beadle said in a Facebook post that Dr. Sarah Beadle, 38, died Wednesday afternoon while hiking with the two school-aged children who were later found safe.

He said authorities contacted him early Thursday to report the discovery of the body in an area of 100-degree heat and no drinking water.

The body was discovered on the north side of the Colorado River, about 1.2 kilometres from the Phantom Ranch lodge at the bottom of the canyon, said park spokeswoman Emily Davis, the new.com.au reported.

The cause of death was not immediately known but there was no indication of foul play, she added.

Sarah Beadle, of Fort Worth, was reported missing on Tuesday after she hiked into the canyon along South Kaibab Trail with the two children, ages 10 and 11. Davis said circumstances of the incident, including how the woman and the children were separated, is being investigated by the National Park Service and the Coconino County Medical Examiner.

Sarah Beadle left the children in a safe place "while she went ahead to get water and some help", wrote her husband, who is a pilot for an emergency rescue service.

"Somewhere along the trail she made a wrong turn and got lost. The park rangers suspect she died of heat exhaustion."

Sarah Beadle passed away sometime yesterday afternoon. She was hiking in the Grand Canyon with Laura and her nephew...

Posted by Scott Beadle on Wednesday, 2 August 2017

The husband said another hiker found the children, gave them water and took them to a camp. He said the kids were unharmed.

"Sarah loved travelling with her family and sharing so many wonderful experiences with all of us," he wrote.

"I thank you all for your continued prayers and support."

Hundreds of co-workers, friends and relatives of the couple responded to Scott Beadle's post with prayers and condolences, and shared their memories of the emergency room physician who worked at Baylor Emergency Medical Center in Keller, a Fort Worth suburb.

Sarah Beadle was described repeatedly as a loving mother, as well as an adventurer who enjoyed hiking, camping and exploring caves.

Her older brother Charles Lawrence Springer told The Associated Press in a telephone interview his sister had been on a trip to take the children to several national parks and they had also visited Yellowstone in Wyoming.

Sarah with her baby. Photo / Supplied via Facebook

Her husband's post included a link to her Facebook page, which showed her skydiving.

Park officials described Sarah Beadle as an experienced hiker who had trekked in the Grand Canyon previously.

But hiking there can be dangerous, with high temperatures at the canyon bottom routinely topping 100 degrees during the summer. There is no potable water available along the South Kaibab Trail between the South Rim trailhead and Phantom Ranch or even creek water to use for cooling, said Jeff Schwartz, a ranger who works in the inner canyon.

Schwartz said rangers advise hikers to hike in the morning or evening when temperatures are milder and there's more shade.

Still, it's not uncommon to have one or two deaths a year primarily due to heat or dehydration, said Schwartz.

"The environment down there is much less forgiving during the summertime," he said.

- Additional reporting: AP