The heatwave of 2003 in Europe helped societies to understand the unexpected impacts of climate change and forced them to consider climate change adaptation in a more systematic and serious approach. Furthermore, severe events like this one showed that the preparedness for climate change impacts was not adequate as it resulted in extremely high mortality. In this context, this dissertation analyses the case studies of three major European cities, London Madrid and Paris, to identify the actions that were triggered after a this strong climate event of 2003 which affected human health, the economy and the environment. Furthermore, this dissertation aims to discuss and analyse the responses to after 2003 and investigate the heatwave plans and adaptation strategies of these cities. In the years that followed all three countries developed National Adaptation Strategies, regional climate plans and heatwave plans. Each city was found to have different responses to climate change but all of them share many similarities among strategies and measures. Heatwave adaptation actions include creation of more green spaces and shading, soft engineering projects, building adjustments, preparedness of social and health professionals and awareness of population. Vulnerabilities in highly urbanised and populated cities like London, Madrid and Paris are found to have a lot in common as they address the same groups. However, responses serve mostly the needs and priorities of each individual case.