Emergency medical service providers serve as the primary immediate response to emergencies of all kinds, including natural disasters and acts of terrorism in the United States, with states serving as the regulatory agencies responsible for training, scope of practice, and continuing education for potential and working EMS providers. This text serves as a comprehensive guide to individuals in training to become emergency medical service providers and complements Emergency Medical Technician (EMT) and Emergency Medical Responder (EMR) courses as the primary classroom text consistent with National EMS Curriculum Standards and other industry guidelines. Each chapter addresses a relevant organ system and its physiology, methods of assessment, treatment recommendations, along with a case study to illustrate the topics at hand. So much of what is involved in emergency medical services is based on practical and applicable knowledge of situations, and these case studies will provide students with exposure to the field work they will be responding to. Written with the context of COVID-19 implications in mind, this is first EMT text of its kind produced after the onset of the pandemic, with considerations and citations from national and international emergency medicine journals to incorporate guidelines and best-practices in light of shifting conditions and expectations.