This chapter explores how the Internet of Things and the utilization of cutting-edge information technology are shaping global research and discourse on the health and wellbeing of urban populations. The chapter begins with a review of smart cities and health and then delves into the types of data available to researchers. The chapter then discusses innovative methods and techniques, such as machine learning, personalized sensing, and tracking, that researchers use to examine the health and wellbeing of urban populations. The applications of these data, methods, and techniques are then illustrated taking examples from BERTHA (Big Data Centre for Environment and Health) based at Aarhus University, Denmark. The chapter concludes with a discussion on issues of ethics, privacy, and confidentiality surrounding the use of sensitive and personalized data and tracking or sensing individuals across time and urban space.