Bushfires have been raging out of control across Australia's most populous state, fanned by intense heat and high winds in "catastrophic" conditions that triggered evacuations.
Of the more than 140 fires burning across New South Wales state late on Tuesday, around 40 of them were uncontained, state Rural Fire Service commissioner Shane Fitzsimmons said in Sydney.
"You don't get conditions worse than this, we are at the catastrophic level," he said.
Prime Minister Julia Gillard warned the nation to keep safe as temperatures soared to more than 45C.
"This is a very dangerous day," Gillard said. "It is very important that people keep themselves safe, that they listen to local authorities and local warnings."
Thousands of firefighters were on standby across New South Wales, while hundreds of people were forced to evacuate homes.
"Catastrophic" level of danger is the most severe rating available. It was introduced after the 2009 Black Saturday firestorm in Victoria, which claimed 173 lives, and means fires will be uncontrollable, unpredictable and fast-moving, with evacuation the only safe option.
Few homes razed
There were fears that the city of Sydney could be threatened next, but so far, mostly scarcely populated areas have been hit.
So far there were reports of just one home being destroyed in the state, at Jugiong near the Australian Capital Territory border. Another two homes were razed in central Victoria state, local media said.
Fitzsimmons said fire crews faced a long night.
"We've still got many hours of very difficult conditions being faced for NSW. That's tonight alone, let alone looking into tomorrow," he told ABC television.
Temperatures soared so high, and are expected to continue climbing in the days ahead, that the Bureau of Meteorology was forced to add new colours - deep purple and pink - to its charts for forecasts above the previous limit of 50C.
Thousands flocked to Sydney's iconic Bondi Beach to escape the heat as temperature hit 41.8C.
No deaths have been reported so far from the latest fires that are a regular occurrence particularly in the hot summer months between December and February.
Wildfires destroyed more than 100 homes in Tasmania over the weekend, and around 40 blazes were still burning across the southern island state but the immediate threat to homes was believed to have passed.