Keith Kennedy, 25, was in stable and improving condition Monday, one day after being found naked, filthy, covered with ticks and bug bites and suffering from dehydration and hypothermia about a mile from his camp for developmentally disabled adults in northwestern Wisconsin.
"He didn't look real good. He really was filthy and his eyes were glazed and he was moving slowly, but he was moving... Considering the alternative, it was awesome," Keith's father Bruce Kennedy told a news conference.
Kennedy's temperature was back to normal from a low of around 84 and he was getting fluids, doctors said. He also was getting antibiotics as a precaution for his tick bites.
"How did he survive? He's a very lucky young man," said Dr. Timothy Whelan of the University of Minnesota Medical Center, Fairview. "It's amazing that he's alive, absolutely amazing that he's alive."
Even though he hadn't taken anti-rejection drugs for a 1995 transplant since he disappeared, Whelan said he was optimistic that the kidney Kennedy received from his father would recover.
Bruce and Linda Kennedy also wonder how their son managed to survive a week in the woods without the skills to fend for himself.
They'll probably never know the answer because Keith Kennedy can speak only four words.
"We're not anticipating him communicating anything about this," Bruce Kennedy said. "He's never spoken in the past tense in his life."
Staffers at the Trade Lake Camp for developmentally disabled adults in Grantsburg, Wis., speculate Keith Kennedy sneaked to the cafeteria to get more popcorn the evening of June 15 and then ran off because he was afraid of getting in trouble.
Kennedy's clothes weren't immediately found. Whelan said it's not unusual for hypothermia victims to think they're hot and take their clothes off.
Linda Kennedy said it wouldn't have been unusual for her son to take his clothes off "if they were wet or awful." Fortunately for him, temperatures were mild.
Hundreds of volunteers joined law enforcement officers, firefighters and medics searching for Kennedy.
By Sunday evening, Bruce and Linda Kennedy had begun discussing with authorities whether to scale back the search. CBS News affiliate WCCO reports that rescue workers were close to ending their search when two St. Paul, Minn., firefighters found Kennedy Monday night.
When Kennedy's parents heard shouts that their son was found, they got in the sheriff's car so quickly they didn't even know he was alive until they were en route to the scene.
"I can't even put it into words," Linda Kennedy said, choking with emotion. "You can only imagine what we've been going through.
"It's parents' worst nightmare, it's my definition of hell on Earth. It's a nightmare that just wouldn't end. And it's just so incredible how everything came together."
The Kennedys said they'll likely stay on either side of their son when they take him out in public again. Kennedy's father said he was going to do some research into tracking devices, and both parents weren't sure they'd let their son go to camp again.
WCCO's Lisa Kiava reports that the parents harbor no ill will whatsoever toward the staff at Trade Lake Camp, saying they understand how difficult it can be to look after people like their son.