AUBURN (AP) — A California runner who walked out of the wilderness after being lost for two bone-chilling nights didn’t follow a basic rule of search-and-rescue — stay put, wilderness experts said Wednesday. Still, he beat the odds.

People such as Robert Root who find themselves helplessly disoriented in the wilderness should get out of the wind and elements, and create a sign that points to their location, survival specialist Skip Stoffel said.

“A moving target is harder to find,” said Stoffel, who trains law enforcement in search and rescue. “Stay put. Find a place and show your face.”

Root, 55, got separated from a group of long-distance runners in remote Placer County on Sunday. He spent Monday searching for help but ended up circling back to the same location, where he shivered through a second night.

On Tuesday, Root made his way to rescuers and introduced himself.

Wearing only a light jacket, shorts and running shoes, he curled up in bushes and staved off shaking by compressing and releasing his muscles. Sheriff’s spokeswoman Dena Erwin said it was amazing that he survived.

As a long-distance runner, Root was physically fit and probably loaded up on carbohydrates before hitting the trail on Sunday, which may have helped sustain him, said Stoffel of Wenatchee, Wash.

Root ate from small supply of energy supplements he brought on the run, officials said. He kept his fingers warm by putting them in his armpits.

Temperatures on both nights plummeted to freezing, said Drew Peterson of the National Weather Service in Sacramento.

Root said that during the ordeal he didn’t feel scared but was frustrated with himself.

“I was running and got lost,” he said in an interview with “Good Morning America.” ‘’I picked the wrong trail and went that way.”

Once he saw people wearing red, Root said he knew he was safe. “I walked up the ridge and said ‘Hi.’”

Root was treated and released at a hospital.

Dr. Eric A. Weiss said people can survive the cold longer than they think — unless they do the wrong things.

In most cases, people should find shelter, stay in one place and crouch down to conserve their body heat, said Weiss, director of Stanford University’s Wilderness Medicine Fellowship.

“Walking around in circles only causes you to lose heat faster,” Weiss said. “And it doesn’t facilitate a rescue.”

Scott Gediman, a spokesman for Yosemite National Park, said as many as 300 people a year get lost in the park nearly 70 miles south of the spot where Root got separated from his group.

Searches in Yosemite can last from 20 minutes to several days, he said.

For anyone entering the wilderness, it’s important to tell somebody where you’re headed and when you expect to return then stay on trails, Gediman said.

That makes the job for searchers much easier, he said.

“The more information you have at the beginning, the better,” Gediman said. “Then you know where to concentrate your efforts, where to put resources.”