Victorians are set to bake as temperatures soar across the state with thunderstorms, strong winds and fire risks adding to the potentially deadly conditions.
Mildura, Swan Hill, Kerang and Echuca in the state's northwest, are tipped to hit 46°C while Bendigo heads to a top of 45°C and Melbourne is forecast to reach 42°C on Friday.
A cool change will bring welcome relief for some areas later in the day but may bring wind gusts up to 100km/h with the potential to exacerbate fires.
Thunderstorms are also expected in parts of central and eastern Victoria in the late afternoon, with the possibility of dry lightning strikes posing a risk of fire.
A total fire ban has been issued for Victoria with extreme fire warnings for the Mallee and the Wimmera.
"If a fire starts it's going to be uncontrollable, it's going to be fast-moving," Emergency Management Commissioner Andrew Crisp said.
But the conditions across the state could prove fatal.
"There will be scores of people who have cardiac arrest or who present in a really severe state by ambulance," Victoria's acting Chief Health Officer Brett Sutton said.
Parents are again being told not to leave children in the car on hot days, as they could be unconscious in minutes.