Ordinarily, you wouldn't be taking survival tips from your podiatrist, however this particular surgical practice might come in handy!
Should you ever find yourself in a situation where someone is bleeding profusely from a lower limb, a Tourniquet may save a life by preventing excessive blood loss. The Red Cross has a fantastic article about how to use a tourniquet properly here. Essentially:
1) Slide tourniquet over limb
2) Pull tail of strapping tight
3) Twist a handle until flow of Bright Red blood stops
4) Secure the Tourniquet
5) NOTE THE TIME
Where does Podiatry come in? The Surgical Principle
When in the operating room, podiatric surgeons use Tourniquets to prevent blood loss to lower extremities when performing various surgical procedures. They employ the rule that, "Tourniquets should be released within 2 hours for 15 minutes to avoid the loss of limb."
"Tourniquets should be released within 2 hours for 15 minutes to avoid the loss of limb."
Essentially, when the lower extremity is deprived of oxygenated blood for too long, it may never regain its function. The same is true in the wilderness. If you are dealing with a life-threatening wound, apply this surgical principle to give the injured party a chance at keeping their limbs upon recovery.