Health experts are warning that Victoria’s approaching El Niño summer could bring a sharp rise in heat-related illness, with higher temperatures and more frequent hot days linked to heart attacks, premature births, stillbirths and worsening mental health.
The warning comes as concerns grow that Melbourne’s emergency departments are not adequately prepared for an increase in heatwaves, which experts say could result in record death tolls.
Professor Ollie Jay, academic director of the Heat and Health Research Centre at the University of Sydney, said extreme heat already cost the Australian economy more than $6 billion a year through lost productivity.
“Basically, we’ve got this hazard, which is extreme heat and chronic hot weather that is growing undeniably in Australia,” he said.
Jay said the risks were being intensified by an ageing population and the growing prevalence of chronic conditions, including cardiovascular and kidney disease. Research published in The Lancet Planetary Health in August found the health effects of heatwaves on people aged over 60 had been underestimated.
Humidity can make conditions more dangerous by preventing sweat from evaporating, while wind and direct sunlight also affect how hot the body feels. Official temperature readings are taken in the shade, Jay said, meaning direct exposure can make conditions feel at least 15 degrees hotter.
“What most people don’t realise is that official temperatures are recorded in the shade,” he said.
How Melbourne can reduce heat risks
Jay said urgent action was needed to reduce exposure to extreme heat, including the use of external shutters, reflective roofs, street trees, urban canopies and shaded outdoor structures.
His research team has assessed more than 70 cooling measures from around the world, including more than 20 building-level strategies, comparing their cost, effectiveness and scientific evidence. Air conditioning, tree cover, outdoor shade and “cool roofs” were among the most effective measures identified.
Melbourne also faces an urban heat island effect, caused by buildings, roads and footpaths that absorb and retain heat. Temperatures can differ by as much as six degrees between parts of the city, particularly in rapidly growing suburbs.
Dr Sarah Robertson, a research fellow at RMIT University’s Centre for Urban Research, said much of Victoria’s housing stock was built before energy-efficiency and thermal-performance standards were introduced.
“We need really we need to focus on improving the quality of our existing housing so it’s thermally comfortable, energy efficient, and affordable for people,” she said.
Robertson said rental property standards due to take effect next year could help drive improvements. The requirements will include ceiling insulation, sealing gaps around doors and windows, and fixed cooling in living rooms at the point of lease or sale.
Dr Rebecca Olive, also a research fellow at RMIT’s Centre for Urban Research, said public spaces had an important role in protecting people during extreme heat and reducing social isolation.
“Often we’re told in extreme heat to stay indoors, pull down the blinds, and stay cool … but this creates great inequities and social isolation, which can link directly to heat-related fatalities,” she said.
Olive said deteriorating local swimming pools, including facilities affected by costly leaks, were placing councils under financial pressure. She has joined four Melbourne councils calling for the Yarra River to be made clean and safe enough for public swimming by 2050.
A government plan to plant 100,000 trees across Melbourne in suburbs with greater exposure to heat has been welcomed by Robertson and Olive. Projects include more than 15,000 trees at Bayview Park in Narre Warren North and 14,000 at Cranwell Park in Braybrook.
Research commissioned by Bupa found that nearly three-quarters of 3,000 Australians surveyed had experienced negative health effects from extreme heat over the previous year. Emotional and psychological stress was identified as the largest health concern, while almost four in five respondents said hot weather was affecting their sleep.
Although 98 per cent of households surveyed had home cooling, about three-quarters said rising electricity costs were forcing them to limit its use.
