Australias worst heat wave and wild fires rage on

Five of Australia's six states combat fires after the worst heatwave in more than 80 years

Authorities evacuated national parks and warned that the temperatures and high winds had led to "catastrophic" conditions.

No deaths had been reported, although officials in Tasmania were still looking for about 100 residents who have been missing since a the wild fires hit the town of Dunalley, destroying around 90 homes.

"We are shaping up for one of the worst fire danger days on record," the New South Wales Rural Fire Service commissioner, Shane Fitzsimmons, said. "You don't get conditions worse than this. We are at the catastrophic level and clearly in those areas leaving early is your safest option."

Catastrophic threat level is the highest rating possible.

Wildfires have destroyed 20,000 hectares or 50,000 acres of forests and farmland across southern Tasmania since Friday. In New South Wales, fires have burned through more than 26,000 hectares or 64,000 acres of land.

In Sydney the temperature hit 41.8C (107F)

The abnormal heat also caused a fire at a nuclear research facility in southern Sydney when cables overheated in a nearby electricity substation. Thousands of homes experienced power outages due to soaring demand.

In Broken Hill, the temp hit 45.1C (113F), and the biggest highway between Sydney and Melbourne was closed by the fires.

The record heatwave has made the Australian Bureau of Meteorology extend its extreme temperature limit, by adding a new pink and purple color to maps to allow for temperatures of above 54C (129F)

Photo: guardian.co.uk