To me, IR is just radiated heat.
The heat source is not touching you, but your body is receiving it, consuming it, and converting to heat that yous feel. That's how campfires warm us. But, we are not totally opaque to IR so it goes in deeper into the body. And if you think about how oximeters work, some of it can go through us. Or, at least our finger.
While air is pretty much transparent to IR, as I recall there are some IR frequencies that are consumed by the atmosphere and do not make it from the sun to the earth's surface.
If you used an electric heating pad on the same area of your body, it would have a similar same effect on your body. But, you would be hottest at the outer skin layer and further in heated up by heat conduction.
While air is pretty much transparent to IR, as I recall there are some IR frequencies that are consumed by the atmosphere and do not make it from the sun to the earth's surface.
If you used an electric heating pad on the same area of your body, it would have a similar same effect on your body. But, you would be hottest at the outer skin layer and further in heated up by heat conduction.