Almost 1200 children and more than 700 animals had to be rescued from Queensland cars last year, according to figures from the state's peak motoring body.
Despite the cases mostly being accidental, temperatures in cars can reach 40 degrees in just seven minutes, the RACQ said in a statement on Friday.
"These high temperatures can have serious health impacts, or even cause death, for those locked inside," RACQ's head of technical and safety policy Steve Spalding said.
Brisbane recorded more than a third of the total number, with 406 children rescued from locked cars last year.
In most cases, parents had given keys to children to play with while they packed or unpacked the car, and the child had accidentally pressed the lock button.
"Please, keep your car keys on you," Mr Spalding said.
He estimated the RACQ rescued around three children and two animals every day.
"There are good and bad days and some days we do many, many more jobs."
If you see a child or animal trapped in a car, call RACQ or emergency services.
