The Budapest Living Lab addresses Urban Heat Islands in Hungary and the Carpathian Basin. The region has a humid continental climate (Köppen classification: Dfb), with warm-hot summers and cold winters. In the entire Carpathian Basin the temperature is rising faster than the European average, and the area is increasingly exposed to drought and heatwaves. Urban Heat Islands (UHI) affect the urban population, their health, energy consumption and lifestyle. Heat islands also have a significant impact on the local economy, especially on tourism. The focus of this Living Lab is on three primary sectors: tourism, health and urban planning. Whilst the city of Budapest has several cultural heritage sites that attract plenty of tourists during the summer months, the increased number of extreme heat days has a negative impact on tourism. Heat islands and increased night-time temperatures, in particular in urban settings, generate a range of negative impacts on human health.