Lightning strikes across Victoria are creating problems for firefighters as weather conditions worsen.
Severe fire conditions are tipped for the state on Friday, but Fire Services Commissioner Craig Lapsley said a repeat of the treacherous Black Saturday scenario was unlikely.
"The whole day is not as severe - that's not to say we won't have fires and we won't have fires that do damage," Mr Lapsley told reporters in Melbourne.
"But it's not the same forecast. It's a severe day, not a code red day, and there is a difference."
On February 7, 2009, bushfires fanned by gale-force northerlies and temperatures in the high 40s killed 173 people and destroyed more than 2000 homes.
The temperature is forecast to reach 44C in Melbourne on Thursday, and 42C with high winds on Friday, before a strong southerly change.
Lightning strikes on Tuesday night sparked more than 250 fires in the state, but fire crews brought most of them under control, despite sweltering heat.
A thunderstorm warning is in place for much of the state on Wednesday night, and Mr Lapsley said crews would monitor any new fires.
A fire burning at Kangaroo Ground, on Melbourne's northeastern outskirts, was brought within containment lines on Wednesday.
An emergency warning was issued for the northwest Victorian towns of Yaapeet and Nypo due to a fast-moving, out-of-control bushfire on Wednesday afternoon and remained in place on Wednesday night.
A spokesman from the State Control Centre said 10 firefighters had been overcome with heat exhaustion.
A total fire ban has been declared for all of Victoria on Thursday and a similar declaration is likely for Friday.