Two trampers were forced to activate a rescue beacon amid life-threatening wind gusts on Mt Aspiring National Park.
The pair were found "exhausted and hypothermic", in conditions so extreme that the rescue helicopter could not land where they were.
"The helicopter pilot said the wind was so bad, the trampers were lying down between each gust of wind and then get up," Rescue Co-ordination Centre New Zealand spokesperson Mark Dittner said.
The trampers were walking on the Gillespie Pass Circuit, in the Young River valley, near Makarora on Saturday.
But as the increasingly extreme wind gusts became life-threatening, the two activated a hired rescue beacon around 1.30pm, prompting a rescue.
An alpine cliff rescue team was flown in a chopper from Wanaka, but the wind was so strong that the helicopter could not land where the trampers were and instead dropped the team off as close as it could.
"There were really extreme conditions up there," Dittner said.
The rescue team walked to the trampers and reached them around 6.30pm last night.
"They were exhausted and hypothermic after being pounded by extremely strong winds," Dittner said.
The team helped the trampers to get to the closest hut, Young Hut, to wait out the night, as another alpine rescue team was sent in.
The group of six - two trampers and four rescue team members - were picked up early Sunday morning by helicopter.
The trampers then drove meet police for a debrief in Wanaka.
Dittner didn't have any more information about the trampers or where they were from.
He recommended those going into the hills to hire a rescue beacon.
"They save lives. In a life threatening situation, it will often mean you can get help in a very short period of time and you can hire these things if you need to."
Dittner also advised trampers to know what weather is expected in the area before they lace up their boots.
"If there's a lesson here, it's to check the weather conditions before you travel. The weather can be highly unpredictable."
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Meanwhile, a search at Arthur's Pass was called off after the missing group made it out of their own accord on Sunday afternoon.
Police were told late last night that a group of trampers were overdue, a spokeswoman said.
The group, believed to be a family, were walking Casey Saddle/the Binser Saddle track in Arthur's Pass National Park.
But they had not returned as expected on Saturday evening and Police were called at 11.35pm.
A rescue operation was to begin at 2.45pm this afternoon but was called off as it appeared the family had made it out of the area of their own accord, the spokeswoman said.