It's feared almost a third of the koalas in the Australian state of New South Wales have been have been killed in the bushfires burning there.
Another heat wave is about to set in with fire conditions expected to reach extreme levels again in the next few days.
Fire crews are doing all they can before the extreme weather hits.
"We are just putting in a back burn containment line to try and prevent the fire from heading towards the coastal villages," said firefighter Nick James.
Military specialists have been deployed to aid the exhausted firefighters.
Dry winds are set to pick up, and temperatures in parts of New South Wales are expected to rise to as high as 45C by New Year's Eve.
Australia's Environment Minister Sussan Ley says up to 30 percent of koalas in New South Wales could have been killed in the fires.
Video of one koala has gone viral after it stopped a group of cyclists near Adelaide.
Tired, and dehydrated, it was filmed climbing up a bike to gratefully receive some much-needed water.
The dam which provides Sydney with 80 percent of its drinking water is under threat. There are fears of contamination if it damages the pipes - or if ash is washed into the water.
Through the smoke, the long term devastation of the bushfires is starting to become clearer.
The owners of one orchard watched on helpless as fire swept through it.
"I was scared. It was terrifying because I've never seen anything like it in all the years I've been here," said Margaret Tadrosse of Bilpin Fruit Bown.
It's already cost them more than a million dollars. That figure will only get higher with reduced crop yields.
"If we replant now, we have to wait four years for a crop. These trees were four years old. So they were just coming into their prime," Tadrosse told Newshub.
The fire's affecting tourism in the Blue Mountains as well - the famous Three Sisters rock formation is totally obscured by smoke, and bushwalks are closed.