Meltdown: homeowners taught about 'massive' heat impact

Cooler homes and a greater understanding of extreme heat's impact on crime are part of a new toolkit to combat the multi-billion-dollar cost of rising temperatures.

The Heat Smart City Plan aims to get communities on the same track to mitigate and adapt to heat, which the greenhouse effect is worsening.

The plan's release on Thursday came amid warnings this summer will be dominated by above-average temperatures.

NSW Environment Minister Penny Sharpe said extreme heat could kill people as well as disrupting the economy.

"There is a massive impact ... there's no one solution to it," she told reporters.

The plan makes 40 recommendations including retrofitting social housing to improve thermal performance and establishing standards for private rentals.

Homeowners would also be educated on how to make their homes cooler.

Better planning in public spaces, including through increasing tree canopy cover, is also recommended to make suburbs cooler.

The plan provides a blueprint for safeguarding communities, the economy and the environment from escalating heat impacts, Greater Sydney Heat Taskforce chair Kerry Robinson said

More than seven out of 10 weather-related hospital visits in the decade to 2022 were because of heat, according to Australian Institute of Health and Welfare data.

"Heat is our most deadly natural hazard," Mr Robinson said.

"Sydney has lacked the co-ordinated arrangements necessary to effectively measure, mitigate and manage the consequences of rising temperatures."

Heatwaves are estimated to cost about $1.4 billion a year in western Sydney through impacts on business and disruptions to transport and other infrastructure, as well as blackouts.

That is expected to grow to $6.8 billion by 2070, as climate change drives more frequent and severe heatwaves.

Rising temperatures also raise the risk of violent crime.

Domestic violence rates are 50 per cent higher when the temperature is 40C, compared to 20C, the plan says.

Several of the initiatives are already underway, the state government said.