Fire authorities are warning Victorian residents to remain on alert for bushfires in several parts of the state, although the extreme heat has passed and all fires have now been downgraded.

A cool change with strong winds and lightning moved across the state on Saturday, with temperatures dropping more than 20 degrees in some places.

• Lives, property under threat in Adelaide
• Warnings as Victoria prepares to swelter
• Firefighters hurt, homes lost in Adelaide

Firefighters stopped the spread of a fire threatening homes at Hastings, Bittern and Crib Point, however a wind change pushed the fire towards houses south of Reid Parade.

About 128ha was burned at Hastings, with some fencing damaged.

Victoria’s Emergency Management Commissioner Craig Lapsley said those who have fought the fires were doing a great job.

“Our firefighters have done really well. In 30 hours we had 327 fires, 326 of those were jumped on and controlled. If you look at the saves and the opportunities of what’s been stopped, it’s been fantastic firefighting by our peoples.”

A fire around the areas of Moyston, Rocky Point, Willaura North, Maroona and Langi Logan burnt through 5,700ha and claimed one house before it was brought under control.

Earlier emergency warnings for the fires near Moyston and Hastings were both downgraded to advice level late Saturday.

Relief centres set up at Lake Bolac and Ararat closed on Saturday evening as residents returned to their homes.

John Haynes from the Country Fire Association (CFA) said Victorians could expect the fire danger to ease as the cold front passes through Victoria over the next few days.

“Hopefully we’ll have no new starts in the north-east of Victoria, but there is some rain potentially that may put any new starts out,” he said.

“[Today] will be a much more pleasant day. Won’t be hot, windy and 40 degrees, so I think it’s low 20s most of the state and a nice, cool breeze, which is good for us as well.”

However, the CFA said the threat had not passed and warned that fire behaviour could become more active in the middle of the day as temperatures increase.

Crews will return to Cherrypool, Brimpaen and Telangatuk and Dimboola, Wail, Pimpino and Duchembegarra today to continue work on the fires.

More than 300 fires have started in the state over the past two days, with extreme heat worsening conditions.

One firefighter was injured while battling the flames at Bittern, near Hastings on Victoria’s Mornington Peninsula, yesterday afternoon.

Paramedics said the man was treated for burns to his arm at the scene, but declined to go to hospital because he wanted to continue working.

Extreme temperatures ravage Victoria

Paramedics treated 32 people across Victoria for heat-related stress in yesterday’s scorching temperatures.

Two children were treated after they were left, unattended, in locked cars.

Authorities said most of those affected were people over the age of 50, including a man in his 80s who spent four hours on the golf course.

State Health Commander Paul Holman said locking children in an unattended car was inexcusable.

“Well unfortunately we’ve still got an influx of heat-related cases today and tragically another couple of children locked in cars which is just unforgivable, quite frankly,” he said.

“We understand it’s inconvenient to take little ones out of the car, but it’s a lot more inconvenient if they’re going to get in trouble and dire consequences if they’re left there for any more than 10 minutes.”

Temperatures are expected to drop today with maximums in the high 20s and low 30s around the state.

Over the border, in South Australia, an out-of-control blaze in the Adelaide Hills has been downgraded to a “watch and act” alert. However, the Country Fire Service is expecting winds to pick up again this morning.