[header] How to apply a tourniquet [title] Discover where the blood is coming from. [step] If you find yourself in an emergency situation where someone (or an animal) is severely injured and bleeding, approach with confidence and reassurance. Helping someone in a life-threatening situation is brave, but you must try to discover and assess the injury as quickly as you can. 
Have the person lie down and find out where the blood is coming from. [substeps] Tourniquets only work on limb injuries, not trauma to the head or torso.