The Internet of Things (IoT) is considered the most efficient way of sending information from devices or smart sensors to the Internet. Monitoring of failures in biomedical equipment is essential to react promptly and avoid adverse events to patients. This study focuses on designing and implementing an IoT system to capture and monitor the environmental variables that influence a highly complex medical device (i.e., computerized axial tomography). The aim of this study is to design and implement a system with a robust and secure three-layer architecture based on service-oriented architecture (SOA) and representational state transfer (REST and RESTful), which allows the safe continuous monitoring of environmental variables in a location where computerized axial tomography (CAT) equipment is installed. The system’s prototype was implemented in a real-context hospital in Bogotá, Colombia. The solution was based on a network of sensors and an electronic circuit board capable of acquiring, processing, and wirelessly sending data associated with the environmental variables to a web service developed for that purpose. The architecture’s implementation was designed to have five sensors recording variables, including the temperature, humidity, vibration, sound, and current of the powered node the CAT was plugged into. The system was tested for 1 month, producing 1,285,257 raw data. In conclusion, having implemented the three-layer architecture based on SOA and the RESTful architecture styles, it was possible to monitor in real time the environmental variables of the location where the medical device was installed.