The Australian climber who has been stuck on Mt Aspiring since Tuesday was found standing and waving as rescue helicopters arrived.
Rescue Coordination Centre NZ Search and Rescue mission coordinator Mike Roberts said "it's extraordinary".
The 29-year-old man - reportedly an Australian army officer - was found waving down the rescue team when the Southern Lakes and Mt Aspiring helicopters arrived at 5pm today, Roberts said.
The man was found alive, with some "slight frostbite", just north of the plateau at Quarterdeck Pass, he said.
A Wanaka Alpine Cliff Rescue team and paramedic are staying with the climber who was found to be "in good spirits", he said.
"The group will be evacuated tomorrow dependent on the weather. His next of kin have been notified."
RCCNZ said that the rescue should serve as a warning for trampers and climbers in winter that they need to be properly prepared and carry a beacon.
The man set off his beacon at the edge of the Bonar Glacier at 12.15pm on Tuesday.
Rescuers were encouraged by movement of the emergency beacon a short distance to the northeast about 2.30pm yesterday.
The climber's beacon had not moved since yesterday and remains at Quarterdeck Pass. However, searchers were very concerned for the man in his late 20s because he was lightly equipped.
A Rescue Coordination Centre New Zealand (RCCNZ) spokesman said this morning a helicopter tried to fly to the man's location at 9am, but had to turn back.
"We've been told he has experience of building snowcaves, so it's possible he's done that," the spokesman said.
"Everything is in place for an immediate response if there is a break in the weather."
Professional guide and former owner of Aspiring Guides, Whitney Thurlow, also believed the climber could have stayed alive if he was in a snowcave.
"If you dig a snowcave people can actually last a long time. The temperature warms up to about zero degrees, which isn't particularly cold compared to outside, plus the big thing is you're out of the wind.
"It's about your only option. A tent wouldn't survive up there in these conditions, it'd blow away."
Thurlow said Quarterdeck Pass was a "very high narrow ramp of snow" that was "difficult to find".
He believed the poor conditions were likely to have played a part in him getting stuck on the pass.
"There's very big cliffs to the left and right of you and if you can't find it then you've got a big problem, which is the problem he's in. You wouldn't be able to find it unless you could see."
The forecast for today is heavy rain, some thunderstorms, northerly winds of 50-60km/h and the temperature at 1800m is between -2degC and zero.
More to come.