As it happened: Residents urged to evacuate immediately as high winds fuel Otways fire; Heatwave breaks Victoria temperature record in regional town

That's where we are going to leave the live blog for today, thanks for sticking with us.

Multiple emergency warnings remain in place for fires burning in Victoria's south-west. You can stay up to date with emergency warnings here.

You can catch up on the latest from today's record-breaking Victorian heatwave here.

Melbourne appears to be cooling down ever so slightly, after a blistering high of 45.6 degrees was felt in the west, at Laverton, just before 5pm.

The mercury peaked at 42.7 degrees in the city around the same time.

The cool change should sweep metropolitan areas later this evening, when the heat is expected to incrementally drop.

But it will still be a warm night, with temperatures not expected to fall below 25 degrees until 3am.

Elsewhere in the state, northern Victorians sweltered through record-breaking heat.

In the Mallee, Walpeup and Hopetoun both reached 48.9 degrees - the hottest day on record in Victoria.

Mildura was more than a degree hotter than it's ever been too, recording a high of 48.6 degrees.

An emergency warning has been issued for communities in the belly of the Carlisle River fire.

Anyone in Gellibrand, Barongarook, Barongarook West, Kawarren, Carlisle River and Gerangamete should take shelter immediately.

The bushfire is travelling in a north-easterly direction towards Gellibrand and Karwarren.

Authorities yesterday door-knocked 1100 properties in the Otways, including the above towns, urging residents to evacuate before sunset.

A south-westerly wind change is currently sweeping south-west Victoria, bringing forecast gusts up to 60 km/h.

Firefighters say unburnt fuel on the ground of the Carlisle River could travel tens of kilometres ahead of the main fire.

"At times there are patches of unburnt fuel, areas that aren't burnt and they can flare up inside the line," Drayton said.

"The stringy barks are notorious for throwing ash and bark, burning bark outside of the containment lines, and that's what our biggest concern was today.

"[It's] the type of vegetation that can be thrown 10, 20, 30, 40 kilometres away depending on the trajectory of the winds."

Firefighters have done an "extraordinary amount of work" to prepare for today's heatwave peak, Drayton said.

"We've had a significant number of firefighters maintaining fire line presence for 24 hours a day," he said.

"The aircraft are used in particular to keep the fires at bay."

Firefighters have managed to keep the Carlisle River blaze, which began on January 10, within its containment lines, Colac deputy incident controller Alistair Drayton said.

"This fire has not escaped or made any large runs and that's what we were really fearful of today based on what had happened only about three or four days ago," Drayton said.

"There's been some incredibly active fire around the fire edge...[but] together with aircraft and large air tankers they've all combined and kept that fire in check."

The fire is now 10,500 hectares in size.

Authorities and crews are now bracing for a south-westerly wind change, which could hit the state's south-west any minute.

The wind change is expected to drastically worsen conditions for firefighters.

There's a new fire burning in Larralea, south of Lismore in Victoria's south-west, sparking an emergency warning for residents to shelter immediately.

Communities in Kariah, Larralea, Leslie Manor, Lismore and Taaraak were urged to take shelter around 3pm after the grassfire became uncontrolled at Camperdown-Lismore Road.

"You are in danger, act now to protect yourself," the Country Fire Authority said.

"It is now too dangerous to leave."Do not get in the car and drive. It is safer to stay where you are."

The blaze is burning from Ettrick Estate Road in a south-easterly direction towards Foxhow Road.

Communities north of the fire zone have been urged to monitor conditions ahead of a wind change expected around 6pm.

The north-west Victorian town of Walpeup has smashed the state's heat record after reaching 48.9 degrees, according to Weatherzone.

Walpeup eclipsed the previous record of 48.8 degrees – reached in Hopetoun on February 7, 2009 – about 3.40pm today.

It is believed the mercury could continue to rise in Walpeup.

Three homes are believed to have been destroyed in the Carlisle River bushfire.

Forest Fire Management's Chief Fire Officer Chris Hardman said it remains unclear if they were family or holiday homes.

"We haven't done a full impact assessment," Hardman said.

Some residents in evacuation zones have stayed behind to defend their properties, authorities have confirmed.

Country Fire Authority (CFA) Deputy Chief Officer Rohan Luke said some people have made the decision to stay despite evacuation warnings in Gellibrand, near the Carlisle River.

"I certainly am aware that some people have chosen to defend their properties," Luke said.

"[But] we have good numbers that have heeded the warnings, moved to relief centres or moved to family members or friends in the area."

Residents from more than 1100 properties in the greater Otways area have been told to leave now.

"There is still time in some of those areas, if you haven't left, to leave now. Leaving now is always the safest option," Chief Fire Officer Chris Hardman said earlier.