Natural hot pools helped keep two American students alive after spending several nights outside in sub-zero temperatures near Arthur's Pass.
Alec Brown and Erica Klintworth, both 21, had been expected to return from a tramp between Monday and Wednesday last week.
Friends reported the pair missing on Saturday evening.
The couple were not found until yesterday. Despite heavy snow and sub-zero temperatures in the area for several days, and not being equipped for extreme conditions, they were in good spirits.
The pair, from Wisconsin and studying at Canterbury University, slept in a hammock tent and regularly jumped into the nearby Otehake River hot springs to keep warm, The Press reported.