Sydney, Feb 10 (IANS): Australia's New South Wales (NSW) state is bracing for bushfires on Friday, as authorities issue high alert warnings for an extreme heatwave.

State Emergency Services Minister Troy Grant said the "catastrophic conditions" will be unlike anything the state has seen since 2013, Xinhua news agency reported.

"Emergency services will be on high alert to deal with those conditions," Grant said.

People are being told to head to large buildings with air-conditioning, such as shopping centres and movie theatres, and warned to stay away from national parks and forests due to heightened safety concerns.

There have also been sweeping fire bans across the state, as temperatures are expected to reach above 40 degrees Celsius across the state, with some areas projected to push close to 50 degrees Celsius on the weekend.

Rural Fire Service (RFS) commissioner, Shane Fitzsimmons warned his fire fighting troops that the next three days will be "difficult" for them, and urged people to have their fire survival plan in place.