SOUTHEAST Queenslanders will once again be cranking up the air con today, with another heatwave to send temperatures soaring.

The nights will be warm and the days even hotter as maximum temperatures range from the low to high 30s.

The temperature will soar to 39C in Beaudesert, Gatton, Laidley and Esk today, while a top of 38C is forecast in Ipswich and 35C for Brisbane.

The Sunshine Coast can expect a top of 33 today and 35 on Saturday before dropping back to 30 on Sunday.

Toowoomba is expecting a top of 36 degrees today, Gympie will hit 38, Bundaberg 34, while Hervey Bay will be cooler on 32 degrees. Warwick will be hot and sunny on 37 degrees today.

Gladstone should expect to hit 34 and Rockhampton 36, while Mackay will be mostly sunny with 31 degrees.

The Queensland Ambulance Service has issued a heat wave warning, saying people could become 'very sick' if they did not take precautions. 

Bureau of Meteorology forecaster Michael Knepp said temperatures would remain high until Saturday.

There will be no respite from the heat overnight either, with minimum temperatures to remain in the mid 20s.

"It's not record breaking in terms of extremes, it's a prolonged period of hot weather," Mr Knepp said.

He said the bureau was not expecting any storms but there was an increased chance on Friday and Saturday, which would be particularly "yuck".

The blistering conditions come after a prolonged heatwave last week, during which a 30-year-old man died of heatstroke while out dirt biking.

Mr Knepp said heatwaves were the most fatal weather phenomenon and urged people to consider turning on their airconditioning, staying indoors or visiting the pool to cool down.