By Steven Deare in Sydney

People have been urged to seek shelter while avoiding sunburn and other illnesses as the weekend heat increases in Australia’s southeast.

Parts of the ACT, NSW, SA and Victoria are on Sunday set for 40C maximums that many West Australians endured last week.

Among the capital cities, Sydney is likely to face the toughest test with temperatures in western suburbs such as Parramatta and Penrith expected to reach 39C. Canberra is forecast to reach 35C.

Melburnians will feel a top of 37C, while people in Adelaide are readying themselves for 36C.

Health practitioners have encouraged people to keep cool and covered and avoid sun exposure, which can cause pain as well as lead to skin cancer.

Staff at the Women’s and Children’s Hospital in North Adelaide have treated 15 patients for severe sunburn in recent weeks.

Doctor Bernard Carney said parents and carers could not be too cautious about children being in the sun.

“It is incredibly distressing for children to be treated for sunburn. They are often in severe pain and require frequent dressing changes,” he said.

“No parent wants to see their child suffer, especially from something that’s preventable.”

Dr Carney encouraged people to keep hydrated, wear a hat and loose clothes, and use sunscreen.

His comments echo the views of Australian of the Year recipients and cancer researchers Georgina Long and Richard Scolyer. The pair have called on Australians to change their attitudes to sun exposure, particularly tanning.

People in regional Australia will experience the highest temperatures on Sunday.

Renmark in SA’s east is set for 44C, while Mildura in Victoria’s west is due for 43C.

While lower temperatures are forecast for much of South Australia and Victoria on Monday, people in western Sydney have no such luck.

Bureau of Meteorology senior meteorologist Angus Hines said people in suburbs such as Penrith and Richmond could expect temperatures of about 39C.

Many people on Australia’s west coast have enjoyed some relief this weekend following heatwave conditions last week.

People in Perth have a forecast maximum of 27C on Sunday. There were two days of extreme temperatures last week, including a record 45.1C in the Swan Valley in Perth on Thursday.

Conditions will remain hot in the north of WA.