The compound 'white-hot' is a descriptive formation from two native English adjectives, 'white' and 'hot'. Its logic is directly visual and physical, originating from the observation of heated metal. When iron or steel reaches an extremely high temperature, its glow shifts from red to a brilliant, incandescent white. This literal, observable phenomenon provided a powerful metaphor, which by the 19th century was extended to describe non-physical states—such as emotions, markets, or trends—that have reached a peak of intensity, excitement, or fervor.

Structure: white (color) + hot (temperature) white: From Old English hwīt, of Germanic origin; related to Dutch wit and German weiss. Functions as a descriptive adjective. hot: From Old English hāt, of Germanic origin; related to Dutch heet and German heiss. Functions as a descriptive adjective.