DAVIS, W.Va. (AP) - Gov. Joe Manchin has pledged the state's resources to the ongoing search for an 18-year-old autistic hiker who has been missing since Sunday.

Manchin visited with the family of Jacob Allen Wednesday evening, spokeswoman Lara Ramsburg said, and promised the state will do what it can to help find the man.

As night fell, the hundreds of volunteers who worked through the day went home, replaced by about 15 seasoned professionals skilled in night searches.

The searchers were glad that overnight temperatures were expected to be warm, and said they weren't bothered by the possibility of a coming cold front.

"We're not planning for another night," said Chris Stadelman, spokesman for the rescue effort. "We're planning to find him tonight."

Allen is very comfortable around people and his parents would not expect him to shy away from rescuers as they call for him, Stadelman said.

More than 300 people, volunteers as well as trained professionals, trudged through the rugged terrain of the Dolly Sods Wilderness Area on Wednesday, shouting for "Jake" to come to them for ice cream, candy bars and other food.

Allen's 22-year-old sister, Brittany, said if her brother sees someone, "he'll be OK." She told the Pittsburgh Post-Gazette in Wednesday's edition that her brother is "very friendly" and "loves people."

Allen wandered away from his parents Sunday afternoon while hiking on the Boar's Nest Trail in the Randolph County section of the wilderness area, which is in the Monongahela National Forest.

He had no food or water with him, but Stadelman said there are natural water sources in the search area, which consists of about 10 square miles of often steep and brush-covered terrain.

Allen's 14-year-old brother, Micah, told the Post-Gazette that the area is "very steep and overgrown."

"If he wandered off, he could be five feet away and you wouldn't be able to see him at all," he said.

Micah Allen also told CNN in an interview that aired Wednesday morning that while his brother is physically fit, he's probably pretty tired and weak by now "so he's probably lying down or sitting down."

Allen was clothed in hiking boots, a long-sleeved T-shirt, a wind jacket and wind pants.

Stadelman said the family and the rescuers remain confident Allen will be found soon, and that there are no plans to scale back the rescue effort.

On Tuesday, Allen's father, Jim Allen, released a statement thanking the search crews for their help and asking the community to keep praying for his son.

Expressions of community support have ranged from prayer vigils at the family's church to Jacob's classmates taking up financial collections to help the rescue effort.

Students at Morgantown High School raised about $500 on Tuesday to buy supplies for the volunteer search teams, including the candy they hope will attract Allen's attention.

"We're all trying to remain positive and put our best thoughts forward," Assistant Principal John Lewis told The Dominion Post of Morgantown. "We'd like to have Jacob back. As a school we're kind of hurting, because he's a great kid and they're a great family."