Adelaide has fallen short of a record top temperature but South Australia has still sweltered through the fourth day of a forecast five-day heatwave.
The city was tipped to have a maximum of 46C on Thursday, very close to the record of 46.1C set on January 12, 1939.
But the top was 44.2C with the mercury dipping to 42.5C by 5pm.
Thursday's high followed tops of 42.1C on Monday, 45.1C on Tuesday and 43.7C on Wednesday.
Friday is also expected to sizzle with the Bureau of Meteorology forecasting a top of 42C before a cool change sweeps in dropping the likely maximum on Saturday to 28C.
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The five days at 40C or above will make it the city's third worst heatwave on record.
In 1908 and 2009 Adelaide sweltered through six days above 40C.
The hottest spot in SA on Thursday was Roseworthy, just north of Adelaide, which had a top of 46.4C.
As the severe conditions continue South Australians have been urged to be vigilant in their efforts to keep cool as fears rise the heatwave will claim lives.
Health officials say there have been no reports of deaths directly linked to the conditions.
But chief public health officer Stephen Christley says it is inevitable that some people who are frail or who have pre-existing illnesses will succumb.
"If you look at what history tells us and the fact that there are vulnerable people in the community, then there's an inevitability that with some people, heat will have contributed to the fact that they will die during this period," Dr Christley said.
So far more than 150 people have been taken to hospital with heat-related conditions, slightly less than the during the heatwave in 2009.
The ambulance service says it is also receiving an extra 150 calls for help each day because of the weather.
Premier Jay Weatherill says people struggling with the heat should not be too proud to call for help.
"There's a cumulative effect here that's going to present itself in threats to people's wellbeing," he said.
Power regulators said the heatwave was putting high demand on electricity supplies with consumption likely to hit record levels.
However they said the system was coping and they did not expect to introduce rolling blackouts.
