A successful search and rescue operation of two climbers who got into difficulty on The Remarkables took more than 12 hours in deteriorating conditions on treacherous terrain.
The two men, both 20 years old, became trapped on the mountain after ice-climbing.
A statement from Otago District Police Search and Rescue said the pair became lost while attempting to walk back to the ski field.
They'd triggered a small avalanche and had made the sensible decision to take shelter in a rock bivvy and call Police for help, Constable Pepper Ruston said.
"Although the climbers were appropriately dressed for climbing and had mobile phones with navigation apps, they were not well-placed to spend the night on the mountain with only a small amount of food and a single silver rescue blanket between them," he said.
Police search and rescue personnel and members of the Alpine Cliff Rescue (ACR) team mobilised in deteriorating conditions, with a severe southwest gale and poor visibility.
He said the plan was to drop the ACR team into the rescue area at 7:30pm and 8:30pm, but both efforts had to be called off due to "high winds and whiteout conditions".
"The decision was then made for a four-person ACR team to go into the area on foot and shortly after midnight, the team was en route from the ski lift towards the climbers' location," he said.
"Conditions were treacherous, with blizzard conditions and a temperature of -8C. The avalanche risk in the area was significant but the ACR team included a member who was qualified to assess avalanche risk and was therefore able to minimise the risk."
By 2:20am the team reported that they were within a few hundred metres of the climbers but were having to move very cautiously due to avalanche risk, he said.
The pair were eventually located at 4.30am and with assistance from the ACR team, walked out to the ski field before being taken back to the SAR base and arriving at 7am.
According to Const Ruston, climbers were "cold, tired and embarrassed".
They had researched the weather conditions before setting out but were caught out by the rapid weather change and had not checked the avalanche risk, he said.
"The climbers were not carrying avalanche gear, nor a first aid kit and they did not have a locator beacon or navigation equipment aside from the phone app," he said.
Queenstown Alpine Cliff Rescue Team coordinator Russ Tilsley said people should do their research before heading into the backcountry.
"Taking the time to check and plan for the worst could save your life - and prevent others from having to risk theirs to come to your aid."
A regional avalanche forecast is available via avalanche.net.nz and anyone going in through a field should check in with the ski patrol to let them know where they are going and when they intend to return, he said.
