Two Frenchmen, one wearing runners, were rescued from Aoraki/Mt Cook after spending an ill-equipped night in the snow.

The men had indicated they would spend Tuesday night at Sefton Bivouac, the oldest hut in the park, but did not arrive, causing Search and Rescue (SAR) to search from early yesterday morning.

Sefton Bivouac is 1650m below the Footstool on the main divide of the Southern Alps. It sleeps four people.

Temperatures had dropped to minus 12deg Celsius over night and there were 40 centimetres of snow in the national park.

The SAR team did not sight the pair until 9.45am and picked them up.

Twizel Senior Constable Les Andrew headed the search and said the two men were ill-equipped to be out on the mountain in the conditions and had misjudged how long it would take them to get to the hut.

Neither man had an ice axe or crampons for the snowy conditions and one had runners on, he said.

"They would have struggled getting down with no equipment."

Andrew was astounded that the pair, who had been advised not to go to up the mountain by the Department of Conservation on Tuesday, decided not to heed the warnings.

"We told them off, but there is not much more that we can do. They [DOC] can't say 'you can't go'. They can only advise them. "

The tab for the cost of the rescue would be picked up by New Zealand taxpayers, he said.

No costs were recoverable, Andrew said.

"We were concerned they had frostbite, but they seem to be fine."

DOC ranger Shirley Slatter encouraged people to talk to DOC before setting out on their excursions and said the department knew the area well and would help people wanting to enjoy the park as much as possible.