This region of the spectrum is sometimes called heat waves . Infrared radiation is energetic enough to affect molecular activity. All warm objects radiate infrared radiation. Special infrared detectors are used to detect heat energy being emitted as a result of metabolic activity. Heat coming off machines and heat producing engines were detectable as infrared radiation.
Infrared radiation has enough energy to affect molecular motions of substances.
Instruments using infrared radiation were designed to determine the identity and structure of compounds. It is interesting that the only part of the electromagnetic spectrum that is viewable by the naked eye is a very narrow band if visible radiation. In essence, what occurs around us that we can detect with our own eyes is a small part of the real world. Visible radiation is associated with energy that can cause chemical reactions to occur. These reactions are called photochemical reactions.