Having a tourniquet, one that you can apply yourself with a single hand (regularly called a CAT: Combat Application Tourniquet), is one of the best items to include in a first aid kit. To apply, slip the wounded arm inside the tourniquet loop so the bleed is 2-3in below the tourniquet. Tighten the strap down enough so that three fingers cannot slip between the tourniquet and the appendage. Secure the strap, then twist the rod until bleeding stops, and secure in the clips. Fasten the rod in place with the TIME strap and mark when the tourniquet was applied. https://www.youtube.com/watch?v=PMfEls2LC8c