Queenslanders have sweltered through record-breaking temperatures over the weekend as the mercury reached more than 40C in some parts of the state.

Brisbane fell just short of its predicted top of 38C, reaching 37.5C on Sunday afternoon before a cool change was expected to sweep through the city.

Bureau of Meteorology forecaster Lauren Murphy said it was 7.5C above the river city’s January average of 30C.

“It’s unusual but it’s certainly not unprecedented,” she said, referring to the city’s record top of 43.2C.

That number was well and truly surpassed in the outback town of Julia Creek, which reached 44.4C on Sunday, just below its record of 45.9C.

But some records were broken in other parts of Queensland.

Residents living in the outback town of Winton endured their hottest overnight temperature on record on Saturday, with the mercury dipping to just 33.1C.

Cloncurry also equalled its all-time warmest night with a low of 32.7C, while Longreach had its hottest night on record since 1902 with a minimum of 31.8C.

The heat resulted in increased work for paramedics.

The Queensland Ambulance Service was called to the NightQuarter markets on the Gold Coast for three separate incidents.

Initial reports claimed each of the trio, including a 45-year-old woman who was taken to hospital in a critical condition, had suffered heat-related illnesses.

But a NightQuarter spokeswoman said she had been advised two had pre-existing medical conditions and the woman who was fighting for life was a market vendor who had suffered a heart attack.

‘We remain in contact monitoring her condition and are supporting the family through this difficult time,” she said in a statement on Sunday.

QAS senior operations supervisor Luke Wyatt urged people to be mindful of hot conditions over the summer and keep an eye on children, the elderly and those doing manual labour.

Mr Wyatt said while heat exhaustion caused people to sweat, feel thirsty, lethargic and possibly nauseous, heatstroke was much more serious and required “time-critical” treatment.

“Their thirst has gone, they’re very dry to touch, they may have an altered level of consciousness, (be) confused, they can slip into having seizures and unconsciousness,” he said.

“That can result in neurological damage, damage to the kidneys and it is a significant and dangerous event.”