Blackout threat eases in NSW, as east coast heatwave continues

The blackout threat for NSW has subsided but catastrophic fire conditions are still predicted as a scorching heatwave settles in across the state.

Demand on the state's power network reached unprecedented levels as temperatures on Friday soared to highs of 45C in western Sydney and 47C in the western Riverina town of Hay.

There were some power outages due to localised faults, but the state was able to avoid rolling blackouts, Energy Minister Don Harwin said.

"I want to thank the people of NSW for their patience and understanding, particularly to those who reduced their energy use this afternoon," he said in a statement.

While the worst has passed, households and businesses should still remain vigilant and limit their energy use over the weekend, Mr Harwin said.

Hunter Valley residents are being told to prepare for "catastrophic" fire conditions this weekend as the state swelters through heatwave conditions.

A total fire ban has been declared for NSW on Saturday and Sunday with Hunter locals bracing for some of the most dire conditions in the state.

Canberra residents, meantime, were reminded to reduce their electricity use this weekend as the temperature rises to 40 degrees in the national capital.

They've been told to limit air conditioning by not going below 26 degrees and turning off all unnecessary lighting, the emergency services agency says.

The NSW Energy Minister had earlier urged residents to go out to the movies or a local shopping centre to escape the heat, in a bid to reduce electricity usage.

"If, for example, people, rather than going straight home and turning on the television and cooking, want to consider going to a movie, going out to a shopping centre, keeping the load low, every bit like that helps," Don Harwin said.

"[I'm] not saying don't put your air conditioner on but instead of putting it on a really ultra low temperature, have the thermostat at 26 or something like that.

"Switch off all of those appliances which are on stand-by, have them switched off. Some of those things can make a big difference and will get us through. We are not out of the woods yet. We have avoided the chance of rolling blackouts so far today and we want to keep doing that and everyone can help make a difference."

Two units at a major NSW power plant were not operational on Friday as soaring temperatures put pressure on the state's energy supply.

AGL Energy confirmed two of the four units at its Liddell Power Station had been shut down due to leaks in boiler tubes.

Heath hazard

Almost 40 people with heat-related illnesses have been admitted to South Australian hospitals in the past two days.

SA Health says 96 people went to hospitals for heat-related problems between Wednesday and Friday mornings, and 39 were admitted.

In Queensland, 16 students from the one school were treated for heat stroke on Friday.

Some of the Moreton Bay students were vomiting, others fainted with two 13-year-old girls and a boy taken to hospital.

Sizzling sport

Saturday's Randwick races have been postponed to Monday due to concerns about the welfare of horses and riders.

Newcastle's A-League soccer match against Melbourne Victory has also been postponed until Monday, while Football NSW has cancelled all Saturday trial games for under-18s and below and shifted under-20s and first grade trials to evening start times.

NSW's three NRL trial matches will however go ahead on Saturday evening, as will the Sheffield Shield clash between NSW and Queensland.

Cricket NSW has cancelled all grades of Premier Cricket, while most school and children's sport has been cancelled.

Heat safety tips

RFS Commissioner Shane Fitzsimmons urged residents in bushfire-prone areas to have evacuation plans in place and to keep track of the fire alert websites and apps.

NSW Health has advised people to stay hydrated, limit physical activity, avoid alcohol and sugary drinks and try to stay out of the sun during the hottest part of the day.

Victorian Health Commander Paul Holman reminded people to "remain vigilant" during the coming days, keeping an eye on elderly people and young children, who are less able to regulate their body temperatures in extreme weather.