Australians have been urged to “call their nan” and check on their mates as the nation swelters over summer.

A new heat safety campaign by Sweltering Cities is calling on people to check in with friends, family and other people at risk of soaring temperatures over summer.

Sweltering Cities is a health promotion charity that works with communities in the hottest suburbs to advocate for more livable and sustainable cities.

Heatwaves are Australia’s deadliest environmental disaster and they’re expected to get worse, the charity’s executive director Emma Bacon said.

Amid cost-of-living pressures, people are being forced to choose between air conditioning and essentials like food and petrol.

“The combination of hotter summers driven by climate change and a cost of living crunch means that more people than ever are worried about whether they can afford to keep cool,” Ms Bacon said.

Add in the fact that Aussies avoid socialising on hot days, according to a 2022 national summer survey, and that leads to a deadly mix.

“Isolation can be deadly for older people, people who live in hot homes, people with disabilities and chronic illnesses, and others.”

So Ms Bacon has put out a call: it’s time to call nan, text your friend who lives in a hot home, or drop in on family who might be struggling to keep little kids cool on hot days.

“All it takes is a text, a call, or a knock on the door,” she said.

The warning echoes earlier calls from ambulance services to take care during periods of intense heat.

“Ensure that we keep up our water intake … try to stay out of the direct sunlight in the middle of the day,” Queensland Ambulance Service senior operations supervisor Matthew Hannabery said.

“Seek cooler areas such as (in) air conditioning or inside houses where it’s nice and shady if you need to use cold compresses just to try to stay cool.”

Summer temperatures have already soared in many parts of the country, as NSW, South Australia and Queensland sweltered through heatwaves in the past week.

The mercury in large swathes of NSW exceeded 43C while inland South Australia and southwest Queensland recorded temperatures reaching the mid 40s.

Birdsville, on the edge of the Simpson Desert, faced near-record high temperatures of 49.4C.

—AAP