When should a tourniquet be applied in emergency situations?

A tourniquet should be applied in emergency situations specifically for life-threatening extremity bleeding that cannot be controlled by other means. The primary purpose of a tourniquet is to stop severe blood loss that poses an immediate threat to life. If the bleeding from a limb is profuse and does not respond to direct pressure or other basic first aid measures, a tourniquet provides a crucial way to occlude blood flow to the extremity, thus stabilizing the patient until further medical aid is available.

In the case of minor cuts and bruises, applying a tourniquet would be unnecessary and could do more harm than good, as it may result in tissue damage or loss of limb function. For non-life-threatening injuries, the focus should be on basic first aid treatments rather than aggressive measures like a tourniquet. Lastly, when a patient is unconscious and cannot respond, it does not inherently indicate the need for a tourniquet, as their condition may not be related to extremity bleeding. Therefore, the application of a tourniquet is specifically warranted only in situations where the bleeding is critical and other measures have failed.