Not sure how to provide you with the info. My first try is a cut-and-paste of the e-mail I received this morning:
replied to a thread you are watching at Space.com Forums
Questions about light
I agree with Cat that heat is light, or infrared photons, and that heat cannot be transported if there are no photons in the infrared region of the spectrum. However, if enough light—say let's blue light—is incident on a surface and is absorbed by it, it can be converted into heat since less of the energy is re-emitted or lost by conduction by the material.
No, since light is made up of energy photons, it cannot spread viruses.
A virus, bacterium, or multicellular organisms form the bodies of a cold or any other sickness. In essence,
a photon of light is incapable of carrying any type of stuff.
The term "light" comes from the fact that light, by definition, moves at the speed of light.
Note that if you click on that link, or otherwise go to that thread, this message does not appear as a post, there.