The Paramedic is a healthcare professional who works in emergency medical situations. A paramedic may be best defined as a medical professional who provides medical care at an advanced life support level in the pre-hospital environment, usually in an emergency, at the point of illness or injury. This includes an initial assessment, a diagnosis and a treatment plan to manage the patient's particular health crisis. Treatment can also be continued en route to a hospital if more definitive care for the patient is required. Paramedics provide advanced levels of care for medical emergencies and trauma. The majority of paramedics are based in the field in ambulances, emergency response vehicles, or in specialist mobile units such as cycle response. Paramedics provide out-of-hospital treatment and some diagnostic services, although some may undertake hospital-based roles, such as in the treatment of injuries.