Air pollution is the biggest environmental health risk in Europe. Smart city initiatives that rely on the Internet-of-Things (IoT) can help addressing the problem. In this paper, we introduce HeyCitI, short for Healthy Cycling in a City using IoT. HeyCitI finds the most healthy path in a city and dynamically adapts the path on the way avoiding areas with higher pollution. To that end, HeyCitI uses up to date information from pollution sensors deployed in the city to dynamically adapt the path. We developed a simulator of HeyCitI that is compatible with DingNet, an IoT infrastructure deployed in Leuven. We give an overview of the HeyCitI and illustrate how self-adaptation improves the air quality for cyclists in a typical scenario. © 2020 IEEE.