One of the main goals of preventive conservation (PC) is to reduce the risk of possible damage produced by the interaction between tangible heritage objects and their conservation environments. This work aims to introduce the European standard EN 15757:2010 as a potential tool for implementing effective museum PC, and it details the potential contributions of both active environmental control and Internet of Things (IoT) technologies in this regard. An application of this strategy is proposed by means of a case study of the conservation of two historical violins, part of a small but significant museum collection in the City of Genoa dedicated to Paganini, whose value is inestimable. According to the standard, monitoring of environmental parameters was carried out for more than four years in the Paganini Hall of Palazzo Doria-Tursi Museum. A remote-control system was implemented, installing digital sensors in the room and in the two showcases. The data were continuously collected through an integrated platform for supervision, monitoring and shared management, based on web-cloud-IoT technology. The analysis of climate data and the assessment of the “historic climate” led to the installation of an active control system on the display cases of the “Cannone” violin and its historical copy. The intervention resulted in a cost-effective improvement in the conservation conditions of the two objects, with an efficient system of warning and safety alarms and a protocol of resolution actions still active and ongoing. The application of IoT systems in monitoring and controlling the indoor climate of heritage collections facilitated the care of the objects at a cost reduction for the institution.