Can a spatial index of heat-related vulnerability predict emergency service demand in Australian capital cities?

The purpose of this paper is to demonstrate a spatial model of population vulnerability (VI) capable of identifying areas of high emergency service demand (ESD) during extreme heat events (EHE).

An index of population vulnerability to EHE was developed from a literature review. Threshold temperatures for EHE were defined using local temperatures, and indicators of increased morbidity. Spearman correlations determined the strength of the relationship between the VI and morbidity during EHE. The VI was mapped providing a visual guide of risk during EHE. Future changes in population vulnerability based on future population projections (2020-2030) were mapped.

The VI can be used to explain the spatial distribution of ESD during EHE. Mapping future changes in population density/demography indicated several areas currently showing high risk will continue to show increased risk.

The limitations include using outdoor temperatures to determine health-related thresholds. Due to data restrictions three different measures of morbidity were used and aggregated to postal areas.

Identifying areas of increased service demand during EHE allows the development of proactive as-well-as reactive responses to heat. The model uses readily available data, is replicable in larger urban areas.

The model allows emergency service providers to work with high risk communities to build resilience to heat exposure and subsequently save lives.

To the authors’ knowledge this triangulated approach using heat thresholds, ESD and projected changes in risk in a spatial framework has not been presented to date.