This book constitutes the refereed proceedings of the 4th IoT Technologies for Health Care on IoT and Big Data Technologies for Health Care, IotCare 2023, held in Leicester, UK, during November 17–18, 2023. The 29 full papers included in this book were carefully reviewed and selected from 93 submissions. They were organized in topical sections as follows: Healthcare Technologies and Innovations; Educational Technologies and Teaching Resources; Internet of Things (IoT) Applications and Systems; IoT and Automation Systems; Medical Research and Analysis.