when a person is injured or become ill,it rarely happens in a hospital with doctors and nurses standing by, In fact ,some time usually passes between the onset of the injury or ill ness and the patient's arrival at the hospital,time in which the patient's condition may deteriorate, time in which the patient may even die. the modern emergency medical services(EMS) system has been developed to provide what is known as "prehospital"or "out-of-hospital"care. its purpose is to get trained personnel to the patient as quickly as possible and to provide emergency care on the scene,en route to the hospital and at the hospital.The Emergency medical technician(EMT)is a key member of the EMS team.