Ann Garbor, age 12, of Camden, N.J., for her question:

HOW IS A TOURNIQUET USED?

A tourniquet is a band of cloth that is used to control bleeding from serious injuries. A tourniquet should be used only with great care and only in times of great emergency.

Doctors say that the use of a tourniquet incorrectly can easily cause gangrene or tissue death. It may also damage uninjured nerves and blood vessels.

Never apply a tourniquet unless all other means of hemorrhage

control have failed and it is apparent that the victim will die unless the bleeding is stopped.

If a tourniquet must be applied, use strips of cloth at least two inches wide. Wrap the material two to six times around the injured limb, just above the wound, between it and the heart. Knot the ends of the material together. Use a stick or similar object on top of this knot with a square knot. Twist the stick to tighten the tourniquet until the bleeding stops.

Do not loosen the tourniquet until a doctor advises you to do so.