This paper charts the challenges and opportunities for design research in the Internet of Health Things (IoHT), by conducting a systematic review of review papers. The Internet of Things (IoT) is already impacting health services and could be the basis for a new healthcare paradigm in the near future. Thus there is a need to engage more designers and design researchers in actively shaping the next generation of development and deployment of IoT in health and care. Following a systematic review of the literature, we present key emerging themes, where design can add value and make a significant contribution to this field. Our findings indicate eight key challenges, which provide several opportunities for design researchers who wish to contribute and lead research in the field of IoHT.