An 80-year-old man is recovering in hospital from severe frostbite after spending the night lost in a roadside ditch near the town of Irma, Alta.

Family members say Harvey Tessman has no idea what happened to the truck he was driving when he set out on the road.

Tessman left his home in Two Hills on Monday morning, planning to drive to Saskatoon to see his son.

Early Tuesday, he was found lying in a ditch along Highway 881, more than 100 kilometres from home.

He was not wearing gloves and suffered severe frostbite to both hands.

"He's not in very good shape," said his stepdaughter, Rachel Farr. "He will probably lose all of his fingers because of that."

The 1994 blue pickup Tessman was driving has not been found.

Farr posted a plea on Facebook for help to find the truck.

"We're assuming he can't travel very far," she told CBC News in an interview. "He usually uses a cane to walk. We have scoured the countryside up and down. The roads, anywhere near there. We just want to get some answers, and I guess if we find the vehicle we can start from there, maybe."

Before the trip, Tessman had no memory problems, his family said, but now can't remember what happened to him or his truck. His keys are also missing.

RCMP are looking for the truck and also aren't sure what happened.

The public is being asked to be on the lookout for this 1994 Chevrolet GMT 400 with licence plate BHV 2061. (Rachel Farr/Facebook)

Farr went to the location where her stepfather was found, just north of Irma.

"The ditch is quite steep there," she said. "So you can kind of see where he tumbled down into the ditch and then he crawled quite a ways on his hands and knees, until a place where he kind of just rested and quit. Gave up, I guess."

Tessman remains in hospital in Viking. His knees were cut from crawling in the ditch and he's covered in bruises.

Harvey Tessman may lose his fingers after suffering severe frostbite to his hands. (Rachel Farr )

Farr said she wonders if her stepfather could have picked up a hitchhiker and something went wrong.

"It's really odd that the vehicle is not near him," Farr said. "He's just physically incapable of walking 15 miles. If it's not near him, then where is it?"

The truck is a blue 1994 Chevrolet GMT 400 with licence plate BHV 2061.

Anyone with information about the missing truck is asked to contact Viking RCMP.