CFA strike teams are working in bushland near the Aberfeldy-Donnellys fire front continuing to cut, clear and douse the area.They work in groups of five, mopping up and blacking out backburning that has been continuing for days to protect properties near the Glenmaggie nature reserve, about 200km east of Melbourne.
Their yellow uniforms are soaked in sweat and black with ash.
CFA spokesman Gerard Scholten says it's tough, monotonous, dirty work.
"This is the real back-breaking work that constitutes firefighting," Mr Scholten said.
"It's boring, yucky work."
There are 70 such crews working around the Gippsland area trying to clear as much fuel as possible before an expected wind change blows in about 5am tomorrow.
They've burned through 180ha in the Glenmaggie nature reserve since Sunday, when crews lit the fire about lunchtime.
Backburning is an important part of controlling bushfires but under Thursday's weather conditions fire officials say it's too dangerous to light any more.
Mr Scholten said the crews in Gippsland are "pretty stretched".
The CFA has a fleet of about 2500 tankers and 150 aircraft but there are fears the fires could ignite anywhere in the hot weather.
The majority of the firefighting resources are on standby at the main fire in the state's southwest, Mr Scholten said.
"These guys are taking off time from their jobs, their businesses to come out here," Mr Scholten said of the volunteers.
"Many of them own their own businesses so it's actually costing them money."
Josh Campbell, from South Morang, has been backburning in Glenmaggie since Tuesday.
His day starts about 8am when his strike team hack undergrowth and douse smouldering bushland while battling the heat.
"The number one reason I joined the CFA was to make a difference," Mr Campbell said.
A lot of his friends fought fires on Black Saturday.
Mr Campbell said it made him want to get involved.
"We've been here on a three-day tour, just blacking out on the southern fire line.
"Just mopping up, just blacking out."
At 11am, temperatures in the nature reserve were almost 25C, with the weather bureau forecasting a high of 35C.
For crews wearing heavy protective gear, heat exhaustion is a serious threat.
Their job involves wading through smouldering undergrowth, often while lugging a fire hose to put out any lingering flames.
Last week, a man was killed and 21 homes were lost in the Gippsland fires, but hundreds more were saved because of the efforts of property owners and firefighting crews.