Fire crews in southeast Australia are reportedly working around the clock to bring bushfires under control before already high temperatures rise and winds pick up again.

More than 100 separate blazes are still burning in New South Wales, affecting at least 300,000 hectares of land and killing thousands of livestock.

Cooler weather has brought some reprieve but forecasters predict another hot period at the weekend.

All national parks, state forests and reserves have been closed to the public. Fires have destroyed buildings in New South Wales, Victoria and Tasmania.

The heat wave moved up the east coast yesterday to Queensland, where a bushfire started on Bribie Island, north of Brisbane.

Temperatures will stay above 30C across the state and are expected to reach the high 40s in some parts today

A senior forecaster told ABC News that rain in part of the state would not be enough to eliminate the fire threat.

New South Wales Rural Fire Service (RFS) superintendent Matt Inwood told the Australian broadcaster: “The cooler conditions have certainly assisted the firefighters on the ground in being able to get in and get some containment lines established around these fires, and indeed back-burn around some of those containment lines.

“We definitely will make the most of those conditions while we have them, but we’re very mindful of the warmer conditions expected over the coming week.”

Seventeen fires remain uncontained in New South Wales, with the worst blazes burning in the state’s south near Yass, Sussex Inlet and Cooma.

There are at least 80 firefighting aircraft, 360 fire trucks and more than 1,000 RFS volunteers trying to contain the fires in the Cooma area, according to local reports.

The Foreign and Commonwealth Office amended its travel advice to Australia, saying: “As extreme heatwave and very strong winds also resulted in numerous bushfires across southeastern Australia in January 2013, including Victoria, New South Wales and southern Queensland.

“Hundreds of bushfires destroyed more properties, hundreds of thousands of hectares of crops and pasture, and killed thousands of cattle. Further extreme fire risk dangers are forecast in coming weeks.”