A condition of the feet produced by prolonged exposure of the feet to water. Exposure for 48 hours or more to warm water causes tropical immersion foot or warm-water immersion foot common in Vietnam where troops were exposed to prolonged or repeated wading in paddy fields or streams. Trench foot results from prolonged exposure to cold, without actual freezing. It was common in trench warfare during World War I, when soldiers stood, sometimes for hours, in trenches with a few inches of cold water in them. (Andrews' Diseases of the Skin, 8th ed, p27).