Wearable devices, e.g. smart-watches, are gaining popularity in many fields and in wellness monitoring too. In this paper we propose an IoT application to alert the medical doctor assigned to a critical unit by using a smart-watch. The wearable device improves the efficacy of monitoring patients at risk in hospital units allowing the medical doctor to access information at any time and from any place. A network was built to wirelessly connect bio-sensing platforms, which measure metabolites concentration in patients’ fluids (e.g. blood), with a dedicated application running on the smart-watch. In case of anomalous measured values, incoming alert notifications are received to ask urgent medical intervention. The main advantage of this new approach is that the doctors, or in general the caregivers, can freely move in the hospital other structures and perform other tasks meanwhile simultaneously and constantly monitoring all the patients thanks to the technology on their wrist.