Medical Incident Officer A person who plays a key role in the UK Department of Health’s major incident plan, in the event of a natural or manmade incident (disaster). The MIO is a senior clinician with appropriate relevant experience and training who is usually taken to the scene by an Ambulance Service vehicle. The MIO has managerial responsibility for the deployment of medical and nursing staff at the scene and will liaise closely with the Ambulance Incident Officer (AIO) to ensure effective management of resources. The MIO is not part of the mobile medical team and should not get personally involved in rescue work. Mobilisation of MIOs is the sole responsibility of the Ambulance Service (AS); each AS maintains an MIO Pool and will invariably deploy doctors from this group when the need for an MIO and support becomes apparent. All receiving hospitals have plans for their individual response to major incidents. Each plan provides for the designation of an MIO. The AS will mobilise MIOs from non-receiving hospitals if pool doctors are unavailable—e.g. in cases of multiple major incidents.