In CUF, your #1 priority is to recognize and stop massive bleeding and get yourself and the casualty to cover and out of hostile fire. Massive bleeding can be identified by a pulsing or steady bleeding from a wound or traumatic amputation of an extremity.
Apply a tourniquet without delay if indicated. Injury to a major vein or artery can result in shock or death from blood loss in minutes. Extremity (arm or leg) hemorrhage is a leading cause of preventable combat death. Using tourniquet(s) to stop the bleeding is essential to the survival of casualties with these types of injuries.
Permanent skin, muscle, and blood vessel damage to the limb is rare (tourniquets are often left in place for several hours during routine surgical procedures). Applying a tourniquet promptly to stop life-threatening bleeding saves lives and may allow the injured Service members to continue to fight while awaiting further care and evacuation. It is imperative that all service members with access to JFAK, etc. be trained in tourniquet use.
Remember: Both you and the casualty remain in grave danger under threat of enemy fire while applying a tourniquet in the CUF phase. Quickly place the tourniquet high and tight on the affected limb. Treatment of non-life-threatening bleeding should be deferred until the Tactical Field Care phase.