In which circumstances must a tourniquet be applied close to the body?

A tourniquet must be applied high on an injury to effectively control severe bleeding in compromised extremities. When a tourniquet is placed high, it is positioned above the site of the injury where the major blood vessels are located. This ensures that the flow of blood to the injury site is significantly restricted, which is crucial in preventing massive blood loss and potentially saving the victim's life.

Applying a tourniquet too low on the arm or leg may not adequately control bleeding if the injury is located higher on the extremity because some blood flow may still reach the injured area. Similarly, placement at a joint or midway on the arm can also fail to effectively occlude the arterial flow, particularly in serious cases of trauma. Therefore, placing the tourniquet high on the injury maximizes its effectiveness in the event of a traumatic injury where significant hemorrhaging is involved.