Two injured climbers stranded nearly 2500 metres up Aoraki/Mount Cook have been airlifted to safety, the Department of Conservation says.
Helicopter crews were able to reach the men just before 8.30am on Saturday after they spent four nights hunkered down in Empress hut, beneath the west face of the mountain.
Aoraki Search and Rescue supervisor George Loomes said the men were in good spirits and had been well prepared for a long stay in the mountains.
"They've done extremely well in trying conditions. They were well prepared with food and supplies for a stay of a couple of weeks," Loomes said.
Rescue in some of country's most rugged terrain
Loomes praised the "strong flying" of the pilots and crews for the Helicopter Line who managed to reach the men through a short window of good weather in extremely challenging terrain.
Poor weather conditions had meant rescuers were unable to reach the men any earlier.
"We waited because we understood they were in a safe location and were in no immediate danger.
"It was a very difficult location, some of the steepest and most rugged terrain in the country. They were directly beneath the west face of Aoraki, beneath multiple faces of a 1000-metre sheer cirque," Loomes said.
"The location is right on the main divide at about 2500m - under Aoraki and Mt Hicks - both of which have faces rising about 1000 metres over the hut. It's right at the top of the Hooker glacier and very challenging terrain."
Loomes said there was only a small window of good weather to reach the climbers.
"We probably had a three-hour window from first light until we got in there and got them so a pretty small window and one that wasn't really in the forecast that we'd been expecting.
"That's closing up as we speak and even on the other side of the mountain, they're stopping flying now," Loomes said.
Loomes said the men were killing time by reading about a month's worth of books and magazines stashed at the hut.
"They were very pleased to be getting out but also quite conscious that they didn't want us to take risks in getting to them. They were in pretty high spirits and really getting into the reading material up at Empress," Loomes said.
He said the rescuers were grateful for the understanding of the climber's family as they waited for safe conditions to extract the men.
"Because the climbers were in a place of safety, prepared for an extended stay and in a stable condition we were able to bring the risk profile right down.
"In similar situations in the past the risk has increased over time to the point where you can get the rescuers into just as much trouble as the people being rescued. So [we're] very conscious of that and very pleased with the result," Loomes said.
He said he was grateful for the contributions of the Timaru Police, The Helicopter Line and the entire Department of Conservation (DOC) for their support of the Aoraki based rescue teams.
"Any individual rescue really relies on all the different parts [of the rescue sector]. I don't think that a team in isolation can achieve a result like this." Loomes said.
'A fantastic result'
Aoraki Police Search and Rescue Sergeant Samantha Stewart said the men had called police on Tuesday afternoon saying they had suffered frostbite but were taking shelter in the hut.
"Both climbers are receiving medical treatment for their injuries and despite what they've been through, they're in good spirits and are very appreciative of the efforts that rescuers have made to get them.
"The pair were caught out by the weather, but thankfully they were experienced in climbing and very well prepared." Stewart said.
She said the pair had been assessed for injuries back at the search in rescue base "within minutes" of being picked up by the helicopter and would be taken to Christchurch Hospital for treatment.
Rescue teams were in regular contact with the pair and their families, she said.
"It's a fantastic result. We made one rescue attempt and considered other windows of opportunity, but each time the weather pushed us back.
"We had a narrow window of opportunity this morning, but we didn't think it would be as good as it was.
"We were stoked to see them getting out of that helicopter, and they were very happy to see us too."
Bianca Bratton from the Mountain Safety Council was well abreast of the challenging terrain.
"It goes without saying that these areas up in our high alpine are some of the country's most remote and wild environments so they are particularly volatile," she told Checkpoint on Friday.
Bratton said the men were in the best place at the hut while they awaited rescue.
The DOC huts "definitely don't have your creature comforts", Bratton said, with no shower, comfortable couch or wifi.
But they did have radios, she said.
Frostbite was a big risk in the cold temperatures, Bratton said. It can affect the fingers, toes, nose or other extremities.
'Real jubilation' in climbing community
An outdoors safety advocate said there was "real jubilation" within New Zealand's "tight-knit" climbing community after the rescue.
New Zealand Mountain Safety Council chief executive Mike Daisley said it was always worrying when people were stranded for so long.
"You always have some worries ... but they were in a really nice safe space, and well prepared.
"But it's still really good news and fantastic efforts from all those involved, the Department of Conservation's Alpine Cliff Rescue Team and Police.
"There's been a lot of coordination and planning, mixed in with a very lucky weather window, otherwise they could have been there for much longer."
Mike Daisley said the huts at that altitude were much more basic than the lower level tramping huts.
"They're much more simple and built for structural safety and very noisy. They're very safe but not relaxing."
But he said the climbers were "prepped with a lot of food and extra clothing - that really helped".
He also urged climbers, skiiers and trampers to always check conditions, with late winter storms becoming more common due to climate change.
He stressed there was no avalanche risk to the stranded climbers, but the late dump of snow had raised the risk.
"Always check the avalanche advisory before you go."