CANBERRA - Residents of South Australia (SA) have been warned to brace for blackouts with temperatures set to soar to record highs. The Australian Energy Market Operator (AEMO) has forecast a power supply shortfall in both SA and Victoria on Thursday evening and for much of Friday, advising the states to seek additional power to prevent blackouts.

Adelaide, capital of SA, was warned that temperatures could exceed the all-time record high of 46.1 degrees Celsius on Thursday while the temperature in Melbourne has been forecast to hit 43 degrees Celsius on Friday.

Audrey Zibelman, chief executive of AEMO, said she wanted people to be "comfortable" in the heat but asked that they limit energy use wherever possible.

"We really ask people to be conscious about not running dishwashers and washing machines, and even cycling off their pool pumps if they can, anything they can do to not use energy that they don't really need to use during the peak time of 4 p.m. to 7 p.m.," she told News Corp Australia on Thursday.

"Even with airconditioners, we want people to be cool and comfortable but also to recognize that you don't have to freeze yourself in your home."

Victoria and SA's ability to meet peak demand during summer has been compromised since a series of coal-fired power stations were closed.

The former SA government purchased diesel generators to supplement the power grid during times of increased demand but they have not yet been used.

Dan van Hoist, SA's energy minister, said the decision on whether they would be used would be made by AEMO.

"At this point in time, based on the AEMO's predictions, we expect that while it may be difficult, we should get through," he told reporters.