Does infrared light appear red to the human eye?
No, heat doesn’t appear red to the naked human eye, because infrared light isn’t in the visible spectrum of colors that humans can see. Heat’s wavelengths are too short for the naked eye to detect, just like ultraviolet’s wavelengths are too long for the nake eye to also detect. However, your skin can detect infrared light and respond to it by sweating when it’s absorbing too much heat.