You'll find portions of the electromagnetic spectrum the human eye can’t see. This consists of thermal infrared radiation. That is radiation with long wavelengths. Every little thing emits thermal radiation - even individuals. Objects such as a stove element on higher, emit radiation from the noticeable spectrum when it glows https://handheldthermalimagers73093.review-blogger.com/52618240/the-fact-about-hand-held-thermal-imagers-that-no-one-is-suggesting