There are actually elements of the electromagnetic spectrum the human eye can’t see. This consists of thermal infrared radiation. That is radiation with prolonged wavelengths. Every little thing emits thermal radiation - even humans. Objects like a stove factor on higher, emit radiation in the visible spectrum when it glows https://augusteouxx.snack-blog.com/29923044/an-unbiased-view-of-hand-held-thermal-imagers