Intelligent Environments (IEs) are expected to have a dramatic impact on our daily lives in the near future. Environments that can assist users in their daily activities, aid the elderly in continuing productive and independent lives, keep people safe and help them make better use of resources can provide great benefits. However, due to the multidisciplinary nature of IEs, the complexity of the technologies involved, and the distinct requirements of different user groups, the development of full scale IEs is a difficult and error prone task. Although a robust design is a fundamental part in the development of an IE, proper supervision of the system for failure detection is important to guarantee the reliability of the systems. In this paper we propose MidBlocks, an event-based component supervising middleware. Through the use of MidBlocks, Intelligent Environments can perform constant supervision of their components and communication links in order to warn users in case of a system malfunction or to perform corrective actions such as dynamic system reconfiguration.