The alarm was raised last night when a 77-year-old man disappeared near to Langsett reservoir, close to Stocksbridge.
He was found two hours later, having strayed from the path.
Inspector Simon Owens, from South Yorkshire Police, said: “Without the massive help offered from Mountain Rescue, who sent 30 people out to help us look for this vulnerable man, this man may have succumbed to the cold weather.
“Thanks to them, the man was found a couple of hours later - cold but uninjured.
“They helped us save a life yesterday evening and I wish to publicly thank them for their support.”