The field of Emergency Medical Services (EMS) is built upon foundational levels that begin with basic CPR/First Aid and end with the advanced care provided by a paramedic. Throughout EMS you will find various levels of education that all focus toward the chain of survival. This chain is a theoretical ideal of how patients can best be treated, whether suffering a heart attack or being involved in a motor vehicle accident. EMT-B is the certification level that comprises the largest population of EMS responders and is often considered the backbone of EMS. EMTs perform basic life saving skills which include: control of bleeding, stabilizing fractures, assisting patients with medications, providing oxygen and other necessities to avoid the development/progression of shock, as well as transport to the emergency room.