The doubts only came in the stifling, suffocating heat of the sauna.

"The sauna was tough," said Lorie Hutchison, who worked her way up to 45 minutes at a time in the sauna in preparation for what is known as "the world's toughest foot race" — the Badwater Ultramarathon. "Especially the last week, my mind was just whirling. It was tough to sit there in the heat."

No, this flight nurse would rather run in the heat, which is why the 44-year-old Salt Lake City resident will undertake the 135-mile race from Death Valley to Mt. Whitney's portal.

It's a race that covers three mountain ranges and thousands of feet in elevation. Runners start at 282 feet below sea level and finish at 8,360 feet above sea level. Temperatures in the area this time of year have reached a record 134 degrees in Furnace Valley, which is where Hutchison was headed for a pre-race meeting Sunday night.

This year is the 31st anniversary of the Badwater race, and two Utahns are among the 83 athletes hoping to finish before the 60-hour time limit.

Many athletes are running for charities, including Payson's Jarom Thurston. The 34-year-old's efforts are on behalf of those with Sturge-Weber Syndrome, a rare congenital, neurological and skin disorder.

Hutchison said she wasn't aware of the charity aspect of the race but decided to undertake the challenge simply to see if she could do it.

"I just read an article saying it was the toughest foot race, and I thought, 'Really? I wonder if I can do that?'" said the veteran of five Wasatch 100 races. "I just wanted to do it for the pure challenge of it."

On the eve of the race, Hutchison she'd only had doubts about her decision last November to enter the race, which starts today in Death Valley, when she began trying to acclimate her body to extreme heat by sitting in a sauna.

"I started with 15 minutes and worked my way up to 45 minutes," Hutchison said. She did much better, she said, when she was moving in the heat. So every night after work, she "went for a short three-mile run just to get myself hot" and then she put on a plastic suit, used by wrestlers to shed water weight. She then drove home, a 45-minute commute, with the heat full blast.

"That was better for my psyche," she said. "I have to drive anyway."

She's also spent the last few days in St. George and Nevada hoping to work out in hotter temperatures.

"It was about 112 degrees in St. George, but Nevada wasn't too hot," she said. "After we hit Las Vegas, the hottest day was maybe 100. It wasn't the Death Valley 120 degrees we were hoping for."

Hutchison said the Badwater challenge is as much about the science of getting the proper hydration and nutrition as efficiently as possible as it is about running, walking or hiking 135-miles. She hopes to do it in 40 hours.