Story highlights Federal government steps in with fuel, personnel to help NSW fire effort

More than 130 fires are burning across NSW during one of the hottest days on record

90% of the Australian state is under "severe" or higher fire warnings

High temperatures and dry conditions have combined to create "dangerous day"

Soaring temperatures and strong winds have combined to create a "catastrophic" fire threat across the southeast Australian state of New South Wales.

Residents have been warned to remain vigilant as temperatures rise towards a predicted high of 43 degrees (109 degrees Fahrenheit) in the state capital of Sydney.

In some areas of the state, winds of more than 70 kilometers an hour (43 mph) were threatening to fan the flames of fires already burning. However, a change in wind direction had caused temperatures in certain parts of the state to fall, offering some relief.

A "catastrophic" fire risk has been declared in four areas of NSW, although the risk across 90% of the state is "severe" or above. A "catastrophic" warning carries the risk of significant loss of life and the destruction of many homes, according to the NSW Rural Fire Service (NSW RFS).

"I cannot say it more plainly: the risk is real and potentially deadly. People need to act now," the service's Commissioner Shane Fitzsimmons said.

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Photos: Australia battles bush blazes, intense heat Photos: Australia battles bush blazes, intense heat Australia battles bush blazes, intense heat – A volunteer Rural Fire Service member from Bungendore RFS washes down a emergency service vehicle on January 8, 2013 in Bungendore, Australia. Hide Caption 1 of 12 Photos: Australia battles bush blazes, intense heat Australia battles bush blazes, intense heat – Fire hoses from Bungendore RFS sit on shelves on January 8, 2013 in Bungendore, Australia. Hide Caption 2 of 12 Photos: Australia battles bush blazes, intense heat Australia battles bush blazes, intense heat – Fire fighters battle a grass fire in Oura, near Wagga Wagga in New South Wales on January 8, 2013. Hide Caption 3 of 12 Photos: Australia battles bush blazes, intense heat Heat map – These weather maps are produced from computer models and are used by forecasters to develop the official weather maps, which contain added features such as cold fronts. Hide Caption 4 of 12 Photos: Australia battles bush blazes, intense heat Australia battles bush blazes, intense heat – Southern states of Australia were hit by soaring temperatures on January 8, 2013, raising the risk of bushfires in the region. Thousands of firefighters were deployed in NSW, Victoria and Tasmania as strong winds fanned flames. Hide Caption 5 of 12 Photos: Australia battles bush blazes, intense heat Sydney swelters during heatwave – Bondi Beach in Sydney, Australia was packed with people attempting to cool down as temperatures hit 43 degrees Celsius (109 Fahrenheit). Hide Caption 6 of 12 Photos: Australia battles bush blazes, intense heat Sydney swelters during heatwave – The soaring temperatures, coupled with strong winds, raised the fire risk to "extreme" or higher across 90% of the state. Hide Caption 7 of 12 Photos: Australia battles bush blazes, intense heat Sydney swelters during heatwave – A lifeguard sign warns beach-goers of the high temperatures at Tamarama Beach in Sydney on January 8. Hide Caption 8 of 12 Photos: Australia battles bush blazes, intense heat Sydney swelters during heatwave – Tourists cover themselves with towels to protect themselves from the sun on one of the hottest days on record. Hide Caption 9 of 12 Photos: Australia battles bush blazes, intense heat Sydney swelters during heatwave – Tommy Robredo of Spain rests next to a fan in between games in his first round match against John Millman of Australia during day three of Sydney International at Sydney Olympic Park Tennis Centre. Hide Caption 10 of 12 Photos: Australia battles bush blazes, intense heat Sydney swelters during heatwave – A pair of Zebras attempts to eat an iced carrot block at Taronga Zoo. Hide Caption 11 of 12 Photos: Australia battles bush blazes, intense heat Sydney swelters during heatwave – The fire rating reached "catastrophic" in four areas of New South Wales, prompting warnings from Prime Minister Julia Gillard that Tuesday was a "dangerous day." Hide Caption 12 of 12

The "catastrophic" fire threat had led many to fear a repeat of "Black Saturday" in 2009, when soaring temperatures and high winds fanned the flames of a series of bushfires across the state of Victoria, leaving 173 people dead and 500 injured, and destroying thousands of homes.

On Tuesday afternoon, the Australian government announced that the state fire service would be granted access to Defence Force bases, fuel and personnel as part of the federal government disaster response plan.

Earlier, Prime Minister Julia Gillard warned it was "dangerous" day and urged people to "stay focused."

"The word catastrophic is being used for good reason," Gillard told CNN affiliate the Seven Network.

"It is very important that people keep themselves safe, that they listen to local authorities and local warnings."

Total fire bans were place in the states of NSW, Victoria and across the whole of Tasmania, the southern island state ravaged by fire in recent days.

On Tuesday afternoon, more than 130 fires were burning throughout NSW, with over 40 of those yet to be controlled, according to NSW RFS.

There were no reports of any homes having being destroyed but authorities warned that the dry, hot conditions were expected to stretch into the night.

"It's a long way ahead -- we've got a lot of daylight left and a lot of nighttime left under these conditions," Fitzsimmons said.

Thousands of firefighters were battling blazes on the ground, and more than 40 aircraft and 250 fire trucks had been deployed, a fire service spokeswoman said.

Thousands more firefighters were on standby in high risk areas, including 21 "strike teams," each consisting of five tankers to assist local brigades.

The fire service said it was relying on people to report fires in their areas, but that surveillance flights were also monitoring the landscape for smoke and flames.

Authorities said residents and tourists had responded well to early warnings to abandon properties under threat.

"If you are in a bushfire risk area -- if you are an at risk location, leaving early is the safest option," Fitzsimmons said.

Record high temperatures and the delayed state of the Australian monsoon season have created a tinderbox out of large swathes of bush and scrub land across the state.

The last four months of 2012 were "abnormally hot" across Australia, according to the Australian Bureau of Meterology. Average maximum temperatures were the highest since records began in 1910.

In the first days of the new year, extreme heat contributed to the spread of fires across Tasmania.

Firefighters are still on alert, tackling a number of blazes, as residents who were in the path of the earlier fires returned to the charred rubble of their homes. More than 100 properties were destroyed or damaged, though authorities warn more may be at risk.

Rescue workers are continuing to search for human remains as around 100 people have still not contacted friends or family, according to Tasmania police.

"It's vitally important that all people who were in the area at the time, and are OK, self-register their details with the National Registration and Inquiry Service operated by the Red Cross," said Acting Deputy Commissioner Donna Adams.

Meanwhile, police have charged a 31-year-old man for allegedly causing one of the worst of the fires by leaving a campfire unattended that was not completely extinguished.