"I find it easy to be motivated on the fire line. If you are working the perimeter you have to be certain the fire isn't going to spread because somebody's house might depend on it," she says.
Karen, who lives in Thames, has worked for DoC for 14 years and travelled before to fight vegetation fires in Canada. With DoC caring for two thirds of New Zealand, vegetation fire fighting is specialist work.
The crews put out spot fires from embers flying over the firebreak lines which are created with bulldozers or controlled fires so there is no fuel for the wildfire.
With ambient temperatures of 39 degrees, Karen says there is a lot of sweat and the constant need to drink water.
The highest risk is from falling trees.
"We're really conscious of that and everybody is checking on each other all the time."
The fires get so big that they generate their own weather system, pyrocumlonimbus.
"It's awe inspiring. The scale is amazing. When I left Australia I heard the fires were twice the size of Switzerland."
Although Karen saw displaced wildlife including iguana and wombats, she counts herself fortunate not to have witnessed too many burnt animals or destroyed homes and was grateful for the welcome received.
"The locals hosted us like royalty," she says.
"Tragedies like this often bring out the best in people, you see the community wanting to help. They would show up and cook us dinner or deliver something delicious. It really felt like the community were pleased to see us there."
Karen was one of two women among the 20, and says New Zealand has a disproportionate number of male to female firefighters, unlike Canada which was more like 50-50.
"I would like to see more women in the field. Everyone brings different strengths and weaknesses and for me, I'm an all-rounder. I do a lot of GPS work and marking the edge of the perimeter."
She says she doesn't consider herself super fit but "can plod happily all day".
"It's more about endurance and team fit."
