Abstract: In Australia heat waves claim more lives than any other natural hazard. To direct population adaptation strategies for a changing climate, it is necessary to be able to identify the location of groups within our population who are most vulnerable to adverse health outcomes associated with extremely hot weather, and to understand factors that influence this vulnerability. This project used multiple social, health and environmental sources of information to create an index of vulnerability. This index has been mapped to create a spatial representation of vulnerability in the city Melbourne. The tool itself is not Melbourne specific and can be transferred to other Australian cities provided threshold temperatures for these regions can be determined. By providing information about the population most vulnerable to heat exposure, this study created the ability to target behavioral adaptation, implement heat wave response plans within the communities with the highest risk. In addition, the spatial distribution of population vulnerability to heat events provided specific information for urban planners about health risks in relation to Urban Heat Islands.