I would like to ask a follow up question to my own question, and might as well do it now.
What would be some techniques, if there are any, to reduce heat radiation from a with no or minimal attenuation of visible light as from the sun or a lamp.
Are there any particular types of glass perhaps, etc.?
Would a water cooled glass jacket or lens have an effect on reducing radiation heat from a lamp, or would this act only as a convective or conductive heat sink?
I'd guess that the temperature of the outside surface of the lamp is fairly important, so if you cooled it with a water jacket you'd probably be off to a good start. I expect that passing your light through water would do away with a large amount of the visible light too.
How about starting with a more efficient lamp (less heat produced)? LEDs should be pretty cool, if you can get enough light out of 'em.
Digital cameras use an IR-blocking filter, which may or may not provide some of the effect you're looking for. It's my understanding that blocking the IR gives a better color balance, and prevents seeing through clothing.
All the forms of radiation are electromagnetic waves, of which a small spectrum are visible to our eyes, namely, from about 380 nm to 780nm. All else is mostly invisible, although even up to 900 nm can be visible with sufficient intensity (in your remaining good eye). Actually, my eyes are still both functional in spite of viewing 850 nm laser light (for very, very, very short periods of time).
Near infrared and infrared are generally attributed to sensed heat, although rattlesnakes supposedly are able to either "see" or direction find warm bodies.
If you look in Edmund Scientific's catalog, there are warm and cold filters. The warm filter is designed to block non-visible wavelengths in projectors and the like.
