Urban overheating is a growing problem, and UNSW researchers have created a national index to measure and then mitigate heat vulnerability in Australia's towns and cities.
On hot days, heat exhaustion can hit quickly, bringing light-headedness, sweat and muscle cramps. If a person is unable to cool down at this point, they might feel nauseous and their heart might race. And if these symptoms are untreated, heat exhaustion can escalate to heatstroke, which can lead to death.
The elderly, the young, and those with pre-existing health conditions are the most at risk.
Heat has a history of making a devastating impact on people. Between 1900 and 2010, extreme heat events claimed more Australian lives than the total number of deaths from all other natural hazards combined.
With 2023 the hottest year ever recorded on Earth, Australia's summers are getting hotter and more dangerous. For example, it is expected that Sydney and Melbourne will have 50°C+ summer days in the near future, with Western Sydney already reaching 48.9°C in January 2020.
What is heat vulnerability?
Urban heat is linked not just to increased deaths and emergency admissions, but also increased energy and water consumption, as people try to cool down.
Some communities are more vulnerable to the effects of heat. This can be due to living in towns and cities more impacted by the Urban Heat Island effect - where high-density urban areas have increased ambient temperature compared to surrounding suburban or rural areas - and also because they have less access to cooling resources such as air-conditioning (with the cost of running air-conditioners an additional barrier to consider).
Heat vulnerability measurements quantify the effects of high temperatures on communities, including heat-related illness, energy consumption and outdoor thermal environments.
