For hardy hikers, a reusable tourniquet
If you were hiking in a remote place with no means of communication and a massive boulder fell on your arm and trapped you for five days with no water, what would you do to stay alive? When Aron Ralston faced that situation a few years ago in Utah's Canyonlands National Park, he went through every option he had before making the decision to sever his arm with a penknife and apply a tourniquet to stop the bleeding.
Medical
His story might make you do a double take before heading out on that day hike: If a potential life-and-death situation requires that you staunch severe bleeding from an arm or leg, will you be resourceful enough (and conscious enough) to fashion a tourniquet out of clothing and other materials on hand, or should you just pack one that's easy to use? OK, this is a little extreme, and most people probably don't think this way. But if you do, there's an easy-to-use option developed for and field-tested by the U.S. Department of Defense.
Cybertech Medical makes a reusable device it calls the Mechanical Advantage Tourniquet, or MAT, made from DuPont Acetel, Nylon 66 and other materials, which can be popped out of a backpack and applied with one hand in less than 10 seconds. The strap goes around the arm or leg, cinched snug, and tightened by turning a winding key-like knob. There's also a quick-release mechanism.
Cybertech says its MAT has survived the impact of combat; adverse conditions like mud and oily grime that would prevent Velcro-based tourniquets from working; and extreme temperatures, from -40 to 200+ degrees Fahrenheit.
The tourniquet retails for $35.50 on the company's site. It weighs less than a quarter of a pound, and the strap comes in two widths, 1 inch and 2 inch.