In this paper the authors describe the implementation and validation of a prototype of an environmental and health monitoring system based on a Wireless Sensor Network (WSN). The solution proposed for our system combines environmental and medical sensors in order to monitor both the surrounding area of the patient and the patient’s health status simultaneously. This feature would allow a comprehensive understanding of the patient’s condition by the specialist caring for the subject. Another key feature of the system is the development of an architecture which provides an easy, viable, cheap and effective way for connecting our environmental and medical sensor network of MicaZ motes to the outside world using Simple Network Management Protocol (SNMP) version 3. A series of experimental scenarios were developed and implemented in a laboratory setting; firstly for evaluating the reactivity of the monitoring system to changes and secondly for understanding the reliability of the data ...