FROSTBITE, a form of mortification (q.v.), due to the action of cold in cutting off the blood-supply from the fingers, toes, nose, ears, etc. In comparatively trifling forms it occurs as "chaps" and "chilblains," but the term frostbite is usually applied only to more severe cases, where the part affected becomes in danger of gangrene. The degree of cold necessary to produce frost bite varies within wide limits and particularly with the associated conditions. A degree of cold that would be borne with impunity by a healthy person in dry air leads to frostbite when (as in the trenches during the World War) the feet are soaked through, movement is limited, and mental anxiety is great. If the individual be underfed in addition a relatively slight degree of cold leads to severe frostbite. An instant application of melting snow, or water, will restore the circulation ; the application of heat would cause inflammation. But if the mortification has gone too far for the circulation to be restored, the part will be lost, and surgical treat ment may be necessary.