He was currently recovering, in hospital but expected to be discharged later today.
Galdamez described how cold and scared he felt throughout his ordeal.
"I was literally just trying to keep warm, pretty much, especially when it started snowing," he said. "I got really scared after that, so I literally just huddled into a circle under my jacket and just tried to keep warm.
"When it started snowing that's when I started getting worried," he said. "It wasn't a good feeling."
He credited his puffer jacket for keeping him alive.
"To be honest if I didn't have that jacket, then honestly I don't think I'd be here. Even with that jacket on it was very very cold, at that point I got very worried for my family, if something happened to me."
About 20 search and rescue staff, with dogs and a helicopter equipped with night vision, combed the mountain last night.
Galdamez had been missing for about 30 hours.
Earlier, his partner Tim Heritage said Galdamez was no stranger to tramping, but he was ''fearing the worst''.
Queenstown as seen from the top of the Skyline gondola. Robert Galdamez when missing after walking up Ben Lomond, above the Skyline complex. Photo / Mark Mitchell
Queenstown police launched a search and rescue operation on Tuesday night, after Galdamez failed to return from a day walk up Ben Lomond.
Senior Constable Terry Wood, of Queenstown, said Galdamez was last seen by his associate just after 3pm.
Galdamez and a friend had arrived in Queenstown on Monday and were scheduled to return to Australia on Saturday.
Heritage understood the pair had initially intended to walk Ben Lomond, above the Skyline complex.
''Apparently his friend only walked 30 minutes with him and didn't want to go any further, or couldn't or something, so she turned back and he went off.
''While he was walking up the mountain I was at work and I was kind of talking to him while working.''
Heritage said Galdamez had sent him some photos of ''up the top'' of Ben Lomond as well as videos of him walking up.
''It looked pretty windy,'' Heritage said.
''He did say he was getting scared and I kept asking him 'Are you all right?' and he didn't respond to my messages.''
After an hour without a response from Galdamez, Heritage contacted the tourist's friend, who said she had tried to video-chat with the missing man, but either something went wrong with the internet, or the battery on his iPad - from which he had been messaging - ran out.
Galdamez, who had been planning to trek to Everest Base Camp in December, had a history of epilepsy, Heritage said.
Galdamez was of El Salvadorean and Laotian descent, but born in Australia.
Wakatipu Tramping Club member Peter Dymock told the ODT it was ''hard to understand'' how anyone could wander off the Ben Lomond track.
The peak, almost 1750m above sea level, was a popular attraction for residents and tourists, accessible either via the One Mile Creek track, or from the top of the Skyline complex.
Dymock said the track from Skyline, where Galdamez had left, was well marked, had a good ground trail and was signposted.
Although it was ''quite steep in places'', he expected a person of average fitness would be able to complete the return trip to Skyline within four or five hours.
A side track led to Moke Lake and although it was ''not obvious'', it was signposted.
Wood said that Galdamez did not have food with him, had very little water and was wearing blue shoes, black sports leggings and a dark green puffer jacket.
