This book constitutes the refereed proceedings of the Third EAI International Conference on IoT and Big Data Technologies for Health Care, IotCARE 2022, which took place virtually during December 12-13, 2022. The 23 papers included in this volume were carefully reviewed and selected from 67 submissions. The papers are present newest results in big data technologies for e-health and for e-care. The papers are organized in the following topical sections: big data technologies for e-health; and big data technologies for e-care.