(CNN)Ten days ago, Joey Peterson wandered out of his parents' rural Wyoming house wearing a sweatshirt and pajama pants.
Search for missing Wyoming boy with autism shifts to recovery effort
It wasn't nearly enough to protect him from the brutal cold, which has dipped well below freezing.
Now authorities are scouring the remote wilderness by both land and air in hopes of finding the 16-year-old boy with autism, even if he's not alive.
"Factoring the time frame, lack of clothing Joey was wearing, no food source and extreme weather conditions, the search for Joey at this time is consistent with a recovery," Natrona County Sheriff's investigator Taylor Courtney told reporters.
Joey was last seen wearing a red hooded sweatshirt and pajama pants. He may not be wearing shoes, Courtney said, but footprints suggest he could have traveled up to 6 miles.
Natrona County Sheriff's Deputy Sean Ellis said the teen does not comprehend how actions have consequences.
"Joseph is autistic who functions at a higher level, but is not self-sufficient and does not problem solve at an age-appropriate level," Ellis said.
Crews have already searched about 240 square miles of the remote terrain. On Saturday, a team found footprints believed to be Joey's miles away from his home, the Natrona County Sheriff's Office said.
"That track provided a general direction of travel through very steep mountainous terrain, and a comprehensive search of that area is ongoing."
On Tuesday, "additional footprints and suspected footprints have been located," the sheriff's department said. "Search teams comprised of mounted searchers, tracking experts, and K9 teams are converging from both sides of an area where Joey is believed to have walked toward."
Searchers are also using drones to try to find the teenager.
Authorities don't suspect foul play in Joey's disappearance, Ellis said.
The 16-year-old is about 5 feet, 9 inches tall and weighs 120 pounds.
Joey has no cell phone or communication devices with him, Ellis said. Authorities ask anyone with information on Joey's whereabouts to call (307) 235-9300.