Flat-earthers often claim that moonlight has a cooling property. I present the results of three independent experiments that test this claim. The results of all three experiments disprove the claim that moonlight cools objects exposed to it. Not only is this claim not supported by carefully conducted experiments, it defies all that we know about the nature of light and energy. Furthermore, this claim has nothing to do with flat-earth cosmology, and easily could be jettisoned by flat-earthers without jeopardizing their model.