A medical emergency can occur at anytime. You must be prepared to act expeditiously and confidently, whether you are in a combat situation, on board a naval vessel, or at the Navy Exchange. This chapter covers the preliminary steps you should follow when managing sick or injured patients. The preliminary emergency steps include triage, patient assessment, and, when needed, basic life support. Other related topics covered in this chapter are breathing aids, shock, diagnosis and emergency treatment procedures for medical conditions and injuries, morphine use for pain relief, and other common emergencies. In the following chapters, diagnosis and emergency treatment procedures for medical conditions and injuries will be discussed.