japan police
A police officer stands guard near a hot spring resort in Yamaguchi prefecture, Japan, Dec. 15, 2016. REUTERS/Toru Hanai

A toddler, who went missing in the woods in western Japan, was miraculously found unharmed after three days on Wednesday. Two-year-old Yoshiki Fujimoto disappeared Sunday morning in the Yamaguchi region while out walking with his brother and grandfather.

Despite an extensive search for the toddler, his whereabouts remained unknown until a 78-year-old volunteer from a neighboring region stumbled upon him and alerted the police. Drones with optical and thermal cameras, search dogs and helicopters were part of the search mission.

Pediatricians and experts were surprised to find the boy had managed to survive the hot temperatures on the island that had topped 30 degrees Celsius between Sunday and Tuesday. The boy, who was spotted sitting on a mossy stone in the middle of a stream, reportedly survived on river water.

“I was most worried about possible heatstroke but the boy may have found shade near the stream and drunk water. It must have been a result of a number of miraculously favorable conditions,” Mieko Miyata, the head of a non-profit organization promoting safety education for children, told local media.

Official Hiroyuki Nishihara at the local hospital treating Yoshiki said "he doesn't have any major injuries, just a few scratches and slight dehydration... but his life isn't in danger and he will be able to leave the hospital very soon."

Eiichi Ishii, a professor at Ehime University’s pediatrics department, was also amazed by the fact that the child managed to survive the three-day ordeal, according to South China Morning Post.

“Water intake is essential for babies and toddlers because they are more vulnerable to dehydration compared with adults,” he said. “The boy may have not sweated much in the shade but it is surprising he hung on in the hot environment. Three days is close to the limit.”

The toddler's family thanked police and volunteers for helping locate Yoshiki

"I couldn't help but squeeze him tight," his mother Mio Fujimoto told a local television station. "I'm so grateful my son returned safely ... He is sleeping tight now, he seemed relieved but tired."

His grandfather told local media: "That this volunteer would come all the way here, all we can do is offer thanks from the bottom of our hearts."