The climbers were plucked from Summit Ridge at 6.45pm on Monday, three hours after the alert was raised.
The climbers were well equipped and experienced and set off a personal locator beacon, factors winch operator for Helicopters Otago Jodie Burton said were key in making for a successful rescue.
"They did the right thing in requesting help when they did," Ms Burton said.
"If they had left it longer then it might not have been as good of an outcome."
The weather conditions and the fact there was still light helped ensure the rescue ran smoothly.
"We got out there at last light so we could do it before it got dark."
Carrying out a rescue at such heights — Mt Cook stands at 3724m — was unusual.
"I’ve been to similar altitudes, but that definitely the highest-altitude winch rescue I’ve been to," Ms Burton said.
Rescue Co-ordination Centre New Zealand senior search and rescue officer Julian Tovey said because of the weather and other factors, the Mt Cook Alpine Cliff Rescue Team called for help from Helicopters Otago’s Queenstown-based emergency medical services helicopter.
"Due to the altitude of where the climbers were located, the crew of the helicopter needed to make it lighter.
"They did this by reconfiguring the machine with less equipment than they would normally carry, to ensure it could safely operate at the altitude required," Mr Tovey said.
The aircraft picked up an alpine cliff rescue team member at Mt Cook village and flew up to Summit Ridge, where the two climbers were winched into the helicopter.
"At an altitude of over 3300m, this was one of the highest-altitude rescues co-ordinated by RCCNZ for some time.
"While there have previously been rescues at the summit, this rescue was just as complex as a summit rescue."
Otago Southland Rescue Helicopter managing director Graeme Gale said the altitude of the rescue made the job unique.
"It is significantly high and you’re dealing with the wind conditions up there.
"There was also a cloud layer sitting below us that the guys had to get through to get up on to where the climbers were."
