More than 80 bushfires are burning across Victoria and South Australia states as temperatures continued to top 40C (104F).
Both states have endured several days of scorching temperatures, with winds helping to increase the speed of the fires.
Victoria Police Chief Commissioner Ken Lay said one person died at their home in Roses Gap in the Grampians region, northwest of Melbourne.
He said the death was fire-related, but gave no other details.
Mr Lay said that 12 of the fires burning across Victoria, Australia’s second most populous state, have been deliberately lit. Arson detectives are investigating.
Victoria Fire Commissioner Craig Lapsley said a blaze burning over 52,000 acres of woodland near the Grampians generated a seven-mile high convection column – a column of rising hot air – that was triggering lightning and sparking spot fires.
Residents in the region had been advised to evacuate their homes, but several people decided to stay and protect their properties, he said.
He added: “They have a right to do so… but they also take on that risk themselves.”