What's So Hot about Red?

A prevailing common-sense hypothesis (the “hue-heat” hypothesis) is that an environment which has dominant light frequencies toward the red end of the visible spectrum feels warm and one with dominant blue frequencies feels cool. Twenty-one students made thermal comfort ratings while wearing red, blue, and clear goggles during three 20-min. runs in which air conditions were “comfortable” and wall temperatures were varied from about 60° to 100° F and back. Four analyses were conducted of the temperatures at which subjects changed their thermal comfort judgment from one category to another. While subject and direction-of-temperature-change effects were significant, no hue main effects or interactions were found. It was concluded that hue produces a strictly intellectual effect, a belief that one is warmer or cooler but does not affect one's thermal comfort.