UPDATE: CONDITIONS are set to worsen for firefighters in the eastern states.

Extreme 40C-plus temperatures are set to return and total fire bans in place for most of NSW and eastern Victoria to cap off a busy week.

As Julia Gillard visited firefighters who were continuing their battle to control a blaze that has destroyed 49 homes near Coonabarabran in northern NSW, their counterparts in other regions and interstate yesterday battled more than 150 fires in extremely hot conditions.

Although homes had been threatened and hundreds of firefighters deployed, no houses were lost in yesterday's fires.

Rural Fire Service Commissioner Shane Fitzsimmons said firefighters in NSW were hoping to strengthen "incomplete and tenuous" containment lines around the fire burning in the Warrumbungle National Park, west of Coonabarabran, ahead of deteriorating conditions today.

"As we have seen here . . . more fire trucks have been responded out to provide protection to properties that are coming under threat with flare-ups in the northeastern part of this fire," he said.

Mr Fitzsimmons said worsening conditions in southern NSW, where temperatures were set to exceed 40C and 80km/h wind gusts were predicted, were a cause of concern for the RFS.

Extreme fire ratings have been issued in the Monaro alpine region and around Bathurst and Orange, west of Sydney, while the state's west and north coast were the only areas without a total fire ban.

In Coonamble, 575km north of Sydney, the Prime Minister said she was touched by the efforts of volunteer firefighters.

"I am overwhelmed by the bravery and stoicism that people are showing in such difficult circumstances," Ms Gillard said.

She also announced disaster payments of $1000 for adults and $400 for each child in the Coonamble, Gilgandra and Warrumbungle local areas, "for people who have lost their homes, for people who have been evacuated, for people who really aren't sure what they are going to do next".

In South Australia, 37 fires had been fought and the Country Fire Service remained concerned about a huge bushfire burning in the state's mid-north last night.

More than 200 firefighters worked through the night to try to control the blaze, which has burned through 2300ha in the Bundaleer Forest, with fears that a change in wind direction expected at midnight could push it towards farming communities such as Jamestown or Georgetown.

Two major fires were troubling authorities in Victoria late yesterday, as temperatures reached 40.7C in Melbourne and 45C in Mildura, in the state's northwest.

Homes were threatened at Pakenham on Melbourne's southeastern outskirts, where a bushfire started in a recycling plant.

At Aberfeldy, 125km east of Melbourne, 40 Department of Sustainability and Environment personnel, five helicopters, three fixed-wing aircraft and 20 tankers were batting a large bushfire, which had burnt approximately 540ha of isolated bushland.

Read more on The Australian.