‘热水’ literally means ‘hot water’—it combines the character 热 (rè), meaning ‘hot’ or ‘heat’, and 水 (shuǐ), meaning ‘water’. Together, they form a common compound noun referring specifically to water that has been heated, typically to a temperature safe for drinking or washing but not boiling. Unlike ‘开水’ (kāishuǐ), which means ‘boiling water’ or ‘water that has been boiled’, ‘热水’ emphasizes warmth rather than sterilization.

This word appears frequently in daily life: ordering drinks, preparing baby formula, taking showers, or discussing health habits like drinking warm water for digestion. In Chinese culture, consuming warm or hot water is often preferred over cold water, especially in traditional health contexts. The term is neutral in register—used equally in casual speech, formal instructions, and medical advice—and requires no special grammatical markers when used as a subject or object.