Prehospital trauma evaluation begins with the primary assessment of airway, breathing, circulation, disability, and exposure. This is closely followed by vital signs and a secondary assessment. Key prehospital interventions include management and resuscitation according to the aforementioned principles with a focus on major hemorrhage control, airway compromise, and invasive management of tension pneumothorax. Determining the appropriate time and method for transportation (eg, ground ambulance, helicopter, police, private vehicle) to the hospital or when to terminate resuscitation are also important decisions to be made by emergency medical services clinicians.