That was partly what saved an Uruguayan man who had been lost in the Andes mountains since May, said Singaporean adventurer David Lim.
Mr Raul Gomez Cincunegui, 58, was found near the Argentina-Chile border, where the Ojos del Salado is.
He survived by feeding on rats and raisins he had with him, and leftovers he found in mountain shelters, according to an Argentinian police report.
Mr Lim, 49, who climbed the world's highest active volcano in 2005, said this was very fortunate.
"He must have stumbled upon some food people happened to leave behind," Mr Lim added.
"They're not government-built shelters fully stocked with supplies. Most of them don't even have a roof.
"Those shelters are just small stone sheds with nothing inside."
The shelters were meant for horse wranglers who take their herd up to the mountains to feed during summer.