‘烫嘴’ literally means 'burns the mouth' and functions as an adjective describing food or drink that is so hot in temperature it causes a burning sensation when eaten or sipped. The first character 烫 (tàng) means 'to scald' or 'to burn', while 嘴 (zuǐ) means 'mouth'. Together, they form a compact, colloquial expression used almost exclusively to warn about or describe dangerously hot edibles—not actual injury, but the immediate, uncomfortable heat felt upon contact.

This term appears frequently in everyday speech, especially in casual dining contexts—like when someone blows on soup before tasting, or warns a child not to bite into freshly steamed buns. It’s not used for non-edible heat (e.g., a hot stove), nor does it imply lasting harm; rather, it signals momentary, sensory discomfort. While vivid and expressive, it’s informal and rarely appears in formal writing or medical contexts.