UPDATE: A SPATE of fires ignited by tractors pulling PTO slashers or by ride-on mowers has infuriated the CFA in central Gippsland.

In declared fire danger periods, tractor and machinery operators must be equipped with knapsacks filled with water or fire extinguishers before they begin work.

Fast spinning mower or slasher blades can spark if the blades strike rocks on the ground and ignite dry vegetation.

The CFA operations manager for Gippsland District 10, Allan Rankin, said today that five of these fires in the past week were preventable had machinery operators taken notice of the restrictions in fire danger periods.

"If they can avoid or postpone working on the machinery, when weather is less risky, that's a good thing,'' Mr Rankin said.

"They have to really be vigilant about what they are doing and where they are operating.

"It doesn't take much for fire in really dry grass for something to really take hold.''

He said it had been frustrating for the volunteers called out to fight the fires.

Mr Rankin said he had talked to the police, who would consider enforcing penalties on people who breached the fire restrictions.

District 10 covers Wellington and Latrobe municipal districts, where the fire-danger period was declared on December 17.

The fire-danger period will begin this Monday for Baw Baw and South Gippsland council area.

CFA state duty officer Brett Boatman this afternoon told Weekly Times Now crews and aircraft were working on several fires.

He said an emergency warning for Warburton had been downgraded to an Watch and Act after 20 fire trucks and aircraft controlled the 2ha blaze.

Thirteen trucks and aircraft were also working at Springfield north of Melbourne and blacking out work is being done at Yandoit.

"It's a bit quieter today, the temperatures aren't as high as previous days," he said.

He said the CFA was working hard before temperatures rose again.

Tomorrow Mildura is forecast for 44C while south of the Divide its forecast for high 30s.

Mr Boatman said there was not a lot of wind forecast for tomorrow but it was tipped to increase on Friday.

The fire danger rating will be severe for most of the state on Friday, extreme in the south west and very high in Gippsland, Mr Boatman said.