As South Australia endures record-breaking heat, some parts of Adelaide are feeling it more than others.

Key points: Urban heat islands are areas of a city that accumulate more heat than others

Urban heat islands are areas of a city that accumulate more heat than others A report finds such areas often coincide with higher levels of higher vulnerability

A report finds such areas often coincide with higher levels of higher vulnerability Experts say more needs to be done to keep temperatures down

In metropolitan Adelaide, some suburbs are home to "urban heat islands", which have higher average temperatures compared to neighbouring suburbs.

Adelaide is currently sweltering through temperatures above 40 degrees Celsius as an extreme heatwave moves through south-eastern parts of the country this week.

Today's temperature has reached 44C in Adelaide while it is forecast to reach 46C tomorrow.

Some Adelaide suburbs worse than others

Heat mapping shows some of the hottest suburbs are also home to the state's most vulnerable people, including the elderly.

Wendy Farmilo lives in Tranmere in one of Adelaide's hottest council areas in terms of urban heat. ( ABC News )

Former aged care worker Wendy Farmilo, 75, lives in Tranmere near Campbelltown in suburban Adelaide — an area overrun with urban heat islands.

Ms Farmilo said because of cooling measures she had put in place, she had managed to avoid the full brunt of the weather this week, but is urging others to take precautions.

"Older people do not drink enough water, they get dehydrated … they feel if they drink too much they might have a bladder problem," she said.

"Make sure you dress in light clothing and try and keep as cool as you possibly can."

According to a report prepared by consultancy firm Edge South Australia, nearly all of the heat islands in Ms Farmilo's council are also home to society's most vulnerable.

"This issue is of greatest significance for Campbelltown, and Tea Tree Gully," the report said.

"In particular, nearly all of the heat islands in Campbelltown coincided with areas of high social vulnerability.

"However, Salisbury had a higher total number of socially vulnerable people living within heat islands."

Urban heat 'one of the biggest killers'

There are several ways to measure urban heat, including the use of satellites, drones and aircraft fitted with cameras.

The SA Government's Urban Heat Mapping Viewer is a publicly available tool used to evaluate how infrastructure choices impact urban environments.

Tusmore, a leafy suburb east of Adelaide, hit 43.9C, compared to Salisbury which reached 46C. ( Supplied: City of Burnside )

"Urban heat is one of the biggest killers of people in our community, more so than any other natural hazard," Edge SA general manager Dr Mark Siebentritt said.

"One of the big strategies we can use to tackle that is the planting of more trees … councils right around South Australia are planting more trees than ever before."

What compounds the problem?

Dark roofs, artificial turf and "large areas of bare ground" contribute to trapping heat in Australian suburbs, Mr Siebentritt said.

"In some areas dry grass can be as hot as bitumen," he said.

Ms Farmilo agreed councils could do their bit to help keep the temperature down in the suburbs.

"I believe they've cut too many trees down to make way for all the infrastructure, and they do not replace them," she said.

Landscape architect and green space advocate Daniel Bennett said boosting tree cover would reduce heat, as well as improving "mental and physical wellbeing".

"Increasing the city's connected tree canopy is one way to achieve a reduction in local temperatures as well as reducing the urban heat island effect," he said.