Adelaide's week-long heatwave has continued with a record-setting fourth December day where temperatures climbed above 40C.
But a cool change is on the way to relieve the baking city which on Saturday again sweltered under temperatures as high as 42.6C.
The change is expected on Saturday night and police are warning people not to compromise security for a chance to cool down the home, reminding them to keep doors and windows locked.
"Sadly, there are a lot of others that take advantage of the hot weather and break into homes via open doors and windows," SA police said in a statement.
An SA ambulance spokeswoman told AAP the service had been busy, but extra staff had been rostered on to help deal with increased demand.
The blistering conditions have been blamed on a stationary high pressure system in the Tasman Sea which has been dragging hot air from the centre of Australia.
The heatwave has left an apprentice carpenter fighting for his life after he collapsed on a building site on Wednesday.
Travis Mellor, 17, was admitted to hospital in a critical condition and remained in a coma on Friday.
He was one of more than 100 hospital admissions over the past three days for heat-related issues with that number set to rise once Saturday's figures are included.
The severe heat has also forced Thoroughbred Racing SA to cancel a scheduled race meeting at Morphettville Racecourse in Adelaide on Saturday.
Wildlife and conservation parks on the Eyre Peninsula are also closed.
