I believe you're about half-way to proving that Thermal Images are
impossible. What next? Santa Claus?


It has already been proven that Santa Claus is impossible. Too many chimneys to
crawl down (let alone up: Claus is morbidy obses as I recall)) in one night...


Perhaps the delta between our positions is that if the temperature increases
are not significant, then I'm assuming that the information is not of value

You miss the important issue. Heat is not dissipated at a point but over a
surface. If I take a soldering iron, for example, and distribute its 40 watts
of heat across a strip of 2 feet by 4 inches, for example, it won't get very
warm in a differential way to ambient.

That re-distribution of heat across a larger surface area is how heat sinks
work.

Ergo, the increase in --temperature-- at a point of measurement--or even across
an area or region-- can be small, even though the total amount of ohmic loss
may be high.

Thermal cameras register differential thermal radiation losses, not convective
losses (per se). And the heat is distributed across a surface, not a point.

You can't take a picture of an antenna outside, and learn much about its ohmic
loss, for example. (Too much convective cooling). Not unless its ohmic loss is
confined to a small area, the air is rarefied and windless, and thus the
temperature differential is a few degrees or more and indicative of bona fide
radiative thermal heating/loss.

Hope you learned something:-)!

Best,
Chip N1IR