I've seen one, used one, lost one. They are/were interesting gizmos. They did or do
exist. I had one a year ago, but knocked it off my down tube, and with no lanyard, it's now sitting somewhere in the woods up on Mossy Bank.
All it did was measure tiny differences in temperature (+ & -). P Voight and I, when it first came out, did a little test with it. I stuck my hand, and the thermal snooper, out the window of a moving car. The Thermal Snooper would go off as we drove through relatively warmer or colder air, beeping or booping . The thing is, my skin registered the difference before the Thermal Snooper did.
That being said, it does react differently than a vario, which to me, is interesting all by itself. I was in the process of analyzing whether it had any advantages over or even if it could compliment the use of a vario alone. Before I could figure it out, I lost mine. P Voight still has one. He could prove they exist, but he's not a member here, as far as I know.
If flyhigh013 were still at home in Ellenville, NY he could maybe get a picture (being Mr. Voight's son) but alas, he's now somewhere in Utah.