One of the most important applications of wireless sensor networks (WSNs) undoubtedly is the emergency management. In particular, sensor nodes can be helpful for both preventing and recovering emergency situations. During critical emergency situations, having a WSN easy to access and manage is a mandatory requirement. So far, sensor networks have been based on custom protocols that make difficult to access and configure sensors by users that are different from the original designers. Today, with the advent of IPv6, integration between a sensor network and Internet becomes feasible. In this paper, we discuss the IPv6 capabilities that can be effectively exploited jointly with 6LoWPAN, and we illustrate a testbed based on an implementation of IPv6 over IEEE 802.15.4. We demonstrate that, by using an open source module we have purposely developed to run over 6LoWPAN, a user equipped with some few common network utilities can remotely access the WSN and change run-time the state and configuration of every single sensor node.