Dozens of wildfires were burning out of control in heatwave conditions across southern Australia, with at least one person confirmed dead.

Fire authorities on Friday said 68 fires were burning across Victoria state and another 16 were blazing across neighboring South Australia state. Both states have endured several days of temperatures exceeding 40C, with winds intensifying the fire risk as they gathered pace.

The Victoria police chief commissioner, Ken Lay, said on Friday that one person died at their home northwest of Melbourne, and that the death was "fire-related".

Residents in the region were advised to evacuate their homes, but several people decided to stay and protect their properties, said the Victoria fire commissioner, Craig Lapsley.

"They have a right to do so ... but they also take on that risk themselves," he said. "They risk the fact that these fires will be very intense and erratic this afternoon."

More than 400 heat exposure cases and 51 heart attacks have been reported in the state since Tuesday - a significant increase on normal figures.

Fire conditions in Victoria are at their worst since 2009, when wildfires killed 173 people and destroyed more than 2,000 homes.

Taking the heat

The Climate Council think-tank said new research had showed that heatwaves were becoming longer and more frequent in Australia, with heat records toppling three times as often as cold records and the number of hot days more than doubling.

"Australia has always had hot weather. However, climate change is loading the dice towards more extreme hot weather," said the council's Will Steffen.

"The current heatwave follows on from a year of extreme heat, the hottest summer on record and the hottest year on record."

Source: Agencies