South Australia heatwave triggers severe bushfire warnings

South Australia is set to swelter as temperatures rise across the state and emergency services go on high alert.

Temperatures in Adelaide will hit 34C and 38C on Tuesday and Wednesday, and will go even higher in some country centres.

Coober Pedy and Marla, in South Australia's north, are set to cop the worst of the hot blast, with temperatures reaching 43C and 45C degrees on Wednesday and Thursday.

A severe bushfire risk has been declared in two South Australian districts.

Very hazardous fire weather conditions are forecast for the northwest pastoral and the west coast and locals are advised to activate their bushfire survival plans.

Ahead of the hot weather, South Australian police have warned against "foolhardy" behaviour which they say is the cause of many bushfires.

"Farm machinery, mechanical breakdowns, burn-offs and lightning strikes have a significant impact," acting assistant commissioner Scott Duval said.

"While some of these are beyond human control, others are simply down to people making poor decisions which can put the entire community at risk.”

The Country Fire Authority says many parts of South Australia face an above average bushfire risk this summer.

"The hotter, drier weather we experienced during spring has rapidly cured vegetation, including in the Adelaide Hills," chief officer Greg Nettleton said.

The State Emergency Service has urged people to look out for vulnerable family, friends and neighbours, particularly the elderly or those with special needs during the hot conditions.

It also called on South Australians to be prepared for heat-related blackouts.

A bushfire is already burning in the Adelaide Hills but is not yet a threat to people or property.

The Country Fire Service says the blaze is burning at Cherryville and is causing smoke in the area.

Locals have been advised to stay indoors and motorists to take care.