The wireless sensor network (WSN) sets a very real benchmark for the Internet of Things (IoT) by utilizing the latest technology to optimize communication and safety systems in hazardous environments. Indeed, WSN is the key technology for IoT. Thanks to the advantages offered by these technologies, in particular, collecting data in real time at low cost, WSNs are gaining popularity in a multitude of fields of application.However, the energy challenge remains persistent, asWSNs suffer from energy scarcity. In this paper,we present an energy-saving design forWSNmonitoring systems known as HEEPS (hybrid energy-efficient power manager scheduling). DVFS (dynamic voltage and frequency scaling) and DPM (dynamic power management) are jointly leveraged to reduce the total energy consumption, as well as a scheduling policy that exploits effectively the resources at the global level. The experiments were conducted with real network traces and hardware models.