Infrared? What Is It? - Pion

Infrared radiation (also IR) is an electromagnetic radiation with a wavelength greater than visible light but shorter than microwave radiation. Our body tissue naturally produces infrared energy, to get warm and regenerate. For example, this is why we can actually visually discern a moving human figure even by night, if we have an infrared camera at our disposal. Infrared radiation penetrates the body as deep as 2 mm below the skin, thus being able to distribute heat to places where it is required. After all, infrared energy is the reason why we can feel the warmth from our sun even on a chilly winter day.

Each year we experience and interesting paradox: in wintertime, when we dwell inside a room with ambient temperature of 18 °C we need to put on a sweater because we are cold. However, in summertime we can easily reside in a room with the exact same temperature wearing just a T-shirt but we don’t feel cold. How is it possible? The answer lies in infrared energy which heats the objects around us; these, in turn, pass the heat on, for example onto our bodies. We are being warmed from the inside.

Infrared waves carry heat, they are thermal. We experience them every day when we feel the heat coming to us from the sun, fire, a radiator or a blistering road. The nerve endings in our complexion are sensitive to temperature, thus being able to distinguish between the body's internal temperature and the external temperature of our skin.

Infrared rays penetrate objects in the room and these subsequently emanate heat back into space. These invisible light waves are also absorbed by skin and spread into the body. The reaction of the tissue is rather specific - it allows in only those waves that react with water inside the human cells and thus generate warmth throughout the whole body. This happens when the infrared rays have the same frequency as the water contained in the cells. This process has a benefitial side effect: it releases toxins from the blood stream, after which they are discharged via sweat, excrements and urine.

Infrared light penetrates the skin a little bit into the human body while common light usually gets reflected. The frequencies close to IR are absorbed by the skin, gently elevating the body's surface temperature. The penetration can be as deep as 1-2 milimetres, increasing the rotational-vibrational of the molecules which absorb the light and resonate with the frequency of cells. And even though we cannot actually feel that we are being heated internally (we perceive warmth primarily at the skin level) we do feel the favourable effects: the heat activates major bodily functions - stimulating metabolism and enzyme activity, blood circulation and so forth.

Surely, these features exhibited by infrared rays played an important part in NASA’s development of materials used for the production of radiant heat during space flights. A similar type of materials is also used in birthing clinics when prematurely born babies need to have artificially maintained temperature.