Nine fire crews have had a sleepless night as a blaze near Lake Tekapo continues raging.
It began at 4am on Friday along State Highway 8 - covering about 100 hectares.
A Fire and Emergency New Zealand (FENZ) spokesperson told Newshub that flare-ups within the containment line of the blaze are posing a major challenge.
Fire incident commander Rob Hands says hundreds of animals died in the fire.
"It's [the fire] consumed an old dwelling - a historical dwelling in a woolshed and a hay barn," he told Newshub on Friday.
FENZ is urging people to be vigilant as hot and dry conditions continue in parts of the country.
Temperatures on Sunday are expected to peak above 30C with gusty winds.
Hands said it's important people stay on top of old fires.
"People need to check the fires that they've had going in the past - even up to a month ago," Hands said. "Depending on fuel, that can reignite and spread."