methods and tools are necessary to plan for a future climate. Geographic information system (GIS) is among other things considered to be an effective tool when identifying vulnerable groups during an extreme weather event. This project aims to show how geographic information and registers in a GIS can be an effective tool for Swedish municipalities at their risk and vulnerability analyses. To show this, vulnerable groups during a heat wave will be identified in a GIS. The study was conducted in Växjö municipality. The problems and difficulties with this project are of great importance in this report as well as the solutions to these problems. The most time demanding difficulty and also a contributing factor to a decrease in efficiency of the system was collecting and the work on the data before importing it to GIS. The analyses in GIS were not very advanced. The conclusion of this report is that GIS can be an effective tool at risk and vulnerable analyses. However there is still a lot of work and planning that needs to be done before GIS can be fully effective during a major disaster.