Body Sensor Networks (BSN) is an important technology in providing ubiquitous healthcare services. These sensors are capable of supplying medical professionals with data collected from a patient outside the hospital environment. Remotely acquired information has enormous application potential and can assist medical professionals to provide fast and accurate assistance to injured people at accidents sites, minimizing the risk of further complications by reducing delays in the diagnosis process. Despite the great benefits of such applications, there is a gap in the state-of-art techniques that allow the creation and testing of such high-level and critical applications. This paper presents a body sensor network simulation environment as a response to that need, providing a tool that plays a key role in assisting the development of critical healthcare applications through an emulated healthcare-specific hardware, which can be used to test applications in a controlled environment, considering the demands of the medical field.