Frostbite and the kindred conditions, trench foot, immersion foot and shelter foot, are almost unknown in England in time of peace. In time of war they suddenly acquire significance. In the war of 1914–18, 84, 670 cases of the first two occurred in the British Army alone; the other two had not then been recognised. Yet in many units cases were few, and in the North Russian campaign between September 1918 and September 1919, only forty-eight men were attacked. They are largely preventable conditions.