The weather bureau warns while conditions in Queensland will be slightly cooler today, the heatwave is not over yet.
The mercury's expected to rise to 43 degrees Celsius at Normanton in the state's Gulf Country and 39 at Mount Isa in the north-west.
Yesterday, the Sunshine Coast recorded its hottest December day at Tewantin with 39.7 degrees, with Nambour reaching 39.2 degrees and Maroochydore 38.1.
A high of 33 is predicted for Brisbane and the Sunshine Coast today.
Senior forecaster Amber Young says firefighters will still need to be on alert.
"We have currently got a fire weather warning current for most parts of the state even where the temperatures have cooled down a bit," she said.
"That is because the air is still dry and the wind is still getting up, so the fire weather warning covers most parts of the state except for the far north, so quite an extensive area due to the warm conditions and dry areas.
"Still expecting temperatures to be at least five to seven degrees above average up in the Gulf Country and tropical interior.
"With that south-easterly wind flow over the south-west and southern interior only expecting temperatures in the mid to low 30s out through those parts, so considerably cooler than what they have been experiencing."
The Queensland Ambulance Service says eight people have been hospitalised for heat stress overnight in the Brisbane, Ipswich and Gold Coast region.
A spokesman say none were experiencing life-threatening conditions.
Tewantin-Noosa RSL club CEO Phil Stephenson says it was twice as busy as usual due to the heat.
"The three bars were relatively busy," he said.
"The Diggers Bar, which is our sports bar, had probably three times the crowd that would normally be in for ... for lunch time etc.
"Our coffee shop is an 80 seater and our restaurant is a 170 and they were both full."
Crews patrolling a bushfire at Burpengary, north of Brisbane, are treating the blaze as suspicious.
It started around 6:30pm (AEST), an hour after a fire devastated a nearby sawmill.
The Queensland Fire and Rescue Service has asked residents in semi-rural areas to be on the lookout for people starting fires in the volatile conditions.
Several crews will return today to the scene of a large grassfire at Rosedale, north of Bundaberg in southern Queensland.
The fire is burning within containment lines and was left unattended overnight.
Firefighters will also return to another grassfire at Brooweena, west of Maryborough.
No properties are under threat from either blaze.
Firefighters say a grassfire that has been burning for several days in the state's southern inland is moving away from rural properties.
One property was evacuated as a precaution after the fire near Miles, north-west of Toowoomba, broke containment lines yesterday.
Acting Superintendent Col Neal says the fire is moving away from the town to state forest.
"At least in there we don't have structures in the way, which is our main priority - protecting peoples houses and things like that," he said.
"Forestry have got crews going out to that fire today and we've got crews in the area and we're bolstering the numbers as well today."
Fires continue to burn in forest on the Western Downs and in inaccessible country north of Toowoomba.
They are not threatening properties.
© ABC 2012
12:52 EST A thick northwest cloudband has brought the best rain in over a year to parts of inland South Australia.