Cool or room temperature is the opposite of lukewarm. The range of day to day useful cold temperatures for water is really narrow. 72 F is room temp. 32 F is fr

Cool or room temperature is the opposite of lukewarm. The range of day to day useful cold temperatures for water is really narrow. 72 F is room temp. 32 F is frozen. Cold is usually below 40. Cool is the stuff in between. There are many more useful temperatures between 72 F and 212 F. Having more words to describe those makes sense.