Is heat really infrared ?

Question

What is the difference between infrared given off by hot stuff and infrared of remote controls. Why is it that infrared remote controls appear to "light up" when seen through a digital camera but other hot stuff appears the same?
How come infrared remote controls dont emit heat then?

Answer 1

They are not the same. Infrared refers to electromagnetic radiation whose wavelength is longer than that of human visible light. The common definition of heat refers to the kinetic energy of particles in matter.

The light from an infrared remote control can impart heat as well as light from a flashlight with the same power output. The remote uses very low power, as you can tell by how long the battery lasts.

Answer 2

I think the main difference is that infrared remote controls give off ONLY infrared light, hot object give off visible light as well (otherwise candles wouldn't work). In addition infrared controls work by modulating a signal (going on an off) while any hot object will give off constant radiation.
Light of any color can heat an object. Only we can't see infrared light, so heat is the only way we can sense it. It doesn't mean that light of a shorter wavelength doesn't carry the energy in a way it can get turned into heat upon absorption.
I assume infrared controls do emit heat, just not much. Also as they are not constantly on but kind of flicker the output would be further decreased if they are .e.g really only half the time you use it actually on.
As to the camera, infrared controls only emit infrared which our eyes can't see, but a digital camera can see.
Hot objects (hot metal) does not only emit infrared radiation, but radiation in the visible spectrum as well. That's why we see hot metal as red, orange or white (color depends how hot it is). You can work with steel which is still hot enough to burn your fingers but it appears black and not glowing, only then it's only emitting infrared but not visible light (If you ever tried welding you will collect experience with that...)