Temperature records have been broken in Port Augusta and Tarcoola as South Australia suffers through an extreme heatwave.

Key points: South Australia on a "code red" alert due to heatwave conditions

South Australia on a "code red" alert due to heatwave conditions Temperature records broken in northern towns

Temperature records broken in northern towns Bats are falling out of trees in Adelaide due to heat prompting warning

The Bureau of Meteorology said Tarcoola, in the state's north-west, reached 49 degrees Celsius at 3:20pm, its hottest temperature since records began in 1903.

Port Augusta — a much larger town — also broke its record with a top of 48.9C at 2:31pm.

The top temperature ever recorded in Australia was 50.7C in Oodnadatta in January 1960.

David Scicluna came to Port Augusta for a cool break from his regular job as owner of the Blinman Hotel, 200 kilometres north.

The temperature gauge at the pub topped out at 50C today.

"Everything's a bit harder to do — even a drink, you've got to drink it quicker because it gets hot pretty quickly," Mr Scicluna said.

"You don't want to be in the direct sunlight.

"I went out to my shed to look at a few things and I thought: 'that can wait'."

He is looking forward to visiting Adelaide tomorrow where it will be a "nice and cool" 40 degrees.

Bats falling out of trees in heat

The extreme heat has also taken its toll in Adelaide, with bats falling from trees in the Parklands.

It comes as the state's fire crews remain on alert during the heatwave.

The SA Government has issued a "code red" alert for the next three days, urging people to take care of the vulnerable during the hot weather.

The temperature in Adelaide peaked at 42.2 degrees.

Health authorities today issued a warning that large colonies of bats and pups, including those in the Adelaide Parklands and Botanic Park, are becoming heat stressed and falling to the ground.

Bats across Adelaide are struggling to cope with the heat. ( AAP: Julian Smith )

SA Health acting director of public health services, Fay Jenkins, said any contact with a bat could be "very dangerous" because the animals can carry deadly diseases.

They should only be handled by trained and vaccinated bat handlers.

"Bats can carry a range of serious diseases that can be transmitted to humans if they are bitten or scratched by an infected bat, including Australian bat lyssavirus (ABLV), which causes rabies," Dr Jenkins said.

"While less than 1 per cent of Australian bats carry ABLV and no human cases have been recorded in South Australia, there have been three reported cases of rabies from ABLV in Australia since 1996, all of which were fatal."

She said the last case involved a Queensland child in 2013.

"In 2018 there were nine bat exposures in South Australia that required precautionary treatment, including rabies immunoglobulin and rabies vaccine, and there have been two already this year," she said.

Botanic Park bat colony has reduced

Natural Resources Adelaide Mt Lofty Ranges ecologist Jason Van Weenen said the risk of more young grey-headed flying foxes succumbing to heat stress had significantly increased over the past five years with the growth of the Adelaide colony.

"The size of the Botanic Park camp has reduced slightly in recent months and is now estimated at around 17,000 bats," he said.

"Temperatures over 40C generally pose the greatest heat stress risk to pups, so there is a high likelihood of a significant number of pups dying over summer.

"If you see a large or small bat on the ground — living or dead — do not touch it under any circumstances."

If bitten or scratched by a bat, take immediate action by washing the wound with soap and water, applying antiseptic and seeking treatment from a GP or emergency department.

Mr Van Weenen said anyone who did come across a dead or injured bat should contact Fauna Rescue on 0475 132 093.

Charges laid over fire

Total fire bans are in place, with firefighters on high alert as the dangerously hot weather conditions continue.

Crews have worked to contain fire grounds at Montacute in the Adelaide Hills and Bute on the Yorke Peninsula.

On Monday, the fire on the Yorke Peninsula managed to jump containment lines due to strong winds and burn 280 hectares of land.

State Duty Commander Brett Loughlin said the conditions are concerning, especially in the Adelaide Hills where thousands of people are expected to gather for the Tour Down Under.

Due to extreme weather conditions, organisers of the tour have removed a 3.4-kilometre finishing circuit on stage one scheduled for today, while the distance of the second stage between Norwood and Angaston, slated for Wednesday, will be reduced by 26.9 kilometres.

Meanwhile, a 33-year-old man has been charged for recklessly causing a bushfire at Naracoorte on Sunday.

Multiple vehicles, sheds and fencing were all destroyed in the blaze on Pistol Club Road.

Investigators have alleged the man was using an angle grinder, which started the blaze.