Highlights

This study illuminates the importance of climate, function, built environment and population characteristics-conscious retrofitting.

Although heatwave-related excess mortality and morbidity have been widely studied, results are not comparable spatially and often longitudinally because of different heatwave definitions applied. The excess heat factor (EHF) quantifies heatwave intensity relative to the local climate, enabling cross-regional comparisons.

Australian cities are experiencing more heat stress in the 21st century than ever before. Public life in a majority of Australian cities suffer from heat stress in urban heat islands. This paper presents the concept of spatial heat resilience as the capability of the built environment to support outdoor activities during heat stress conditions.

Outdoor thermal discomfort pushes citizens into air-conditioned buildings and causes increased demand for water and electricity in the majority of Australian urban heat islands. Citizens’ spatial and activity preferences during heat stress conditions are under investigation in this paper.

Highlights

Climate change projections indicate a likely 3.8°C increase in the average temperature in Australia by 2090. During summer, outdoor heat-stress causes significant thermal discomfort, altering outdoor living preferences. This paper aims to explore the neutral and critical thresholds for outdoor thermal adaptation.

During summer heatwaves, public spaces are frequently warmer than human thermal comfort preferences in a majority of Australian Cities. Citizens’ preferences of public space elements and supportive features during heat-stress conditions are under particular focus in this paper.

Australia has had seven extreme heatwaves since the beginning of the 20th century. During heatwaves, public spaces in cities are frequently warmer than is confortable for humans. The regional warming projection of 2-5°C in Australia (by 2070) will be added to an existing 4-8°C extra heat in higher urban densities.

As the frequency and intensity of heatwaves are growing in Australia, strategies to combat heat are becoming more vital. Cities are exposed to urban heat islands (UHIs) due to excess urbanisation. In this study, a definition of urban heatwave (UHW) is conceptualised to investigate the combined impacts of heatwaves and UHIs.