A cool change might have been a saving grace for Victorians as temperatures halved within minutes but it hasn't been enough to stop fires raging across the state.
Some northern centres hit 46C and Melbourne reached 42.6C on Friday with a cool afternoon change sweeping through along with wind gusts forecast to reach up to 100km/h.
"The danger period is not over," Emergency Services Minister Lisa Neville said as the heat eased.
"We still have fire in the landscape and potential for further fire with the storms coming through, and dry lightning."
An uncontrolled blaze in the state's east has threatened lives and homes in Fulham, Kilmany, Kilmany South and Pearsondale with an emergency warning urging people in the area to "act immediately to survive".
A watch and act warning has been issued for Stradbroke West, Willung and Willung South and other parts of the state with residents urged to leave before it's too late.
Ms Neville told 3AW the fire was moving "quite quickly" and 12 aircraft and nearly 20 other appliances were still trying to bring it under control.
A house fire in Strathbogie, in the state's northeast, sparked an out-of-control bushfire in "a very difficult area to control it if we lose track of it", she added.
Thunderstorms are also expected in parts of central and eastern Victoria, with the possibility of dry lightning strikes posing a further fire risk.
Victorian SES state controller Tim Wiebusch warned that any blazes could become "uncontrollable and unpredictable".
Emergency Management Victoria Commissioner Andrew Crisp said numerous blazes had been sparked by unattended campfires.
"This behaviour has the potential to create such significant impact that it really is dumb. It should not happen."
Melburnians welcomed the cool change as the temperature dropped about 20C within 40 minutes late on Friday afternoon.
Authorities have already pulled several children from hot cars including two from the same vehicle parked in a shopping centre in Melbourne's southeast.
Australian Associated Press
