Emergency responders and volunteers searching for an autistic hiker in a national park have found his hat, a day after he strayed from his parents during a hike. The hat was found Monday close to where Jacob Allen, 18, had last been seen Sunday afternoon, search group spokesman Chris Stadelman said from the command post near Davis. "We're trying not to read into it too much one way or the other," he said.

Allen wandered ahead on the Boar's Nest Trail while hiking with his parents, Jim and Karen Allen. He didn't answer when they called his name, Stadelman said. Allen's mother described him as severely autistic.

More than 50 emergency responders and volunteers were focusing on 10 square miles of the Monongahela National Forest, an area with rugged terrain that includes sections of thick brush and steep inclines.

"Some of it is back country where it's so thick you can't see five feet in front of you in the daylight," Stadelman said.

Teams from the Army Reserve and the Morgantown-based Mountaineer Area Search and Rescue were combing the wooded area Monday night as a helicopter with infrared technology hovered overhead, he said.

The Allen family, of Morgantown, visits Dolly Sods Wilderness Area a couple times a year, and Jacob is in good physical condition and likes to hike, Stadelman said.

The family declined to speak with the press, but thanked searchers for their efforts and asked for the public's prayers, Stadelman said.

Temperatures dropped to 38 degrees overnight, and rose to the high 60s Monday afternoon. Lows near 45 degrees are expected Monday night.

Allen was wearing a long-sleeved T-shirt, a wind jacket and pants, and hiking boots. He had no food and water.