Not sure if this is the right place to ask (mods move please if inappropriate)? Just wondering if anyone has advice on a good but cheap handheld thermal camera for checking cold spots in a home? It doesn't need to be lightening fast but it just can't freeze and brick itself like some of the no name brands on eBay. This also includes not buying the cheap ones that just shows a poor image of rainbow blobs.

I have an EOTech X320.
For inspections and maintenance of plumbing, electrical, and mechanical etcetera,  it has two features that I find very useful. First, the thing will focus to a couple feet. Second, there is a small crosshair (if you enable it) in the center and the scope will report the temperature at that point.
The color pallet is OK, but the color ranges are set manually and are fixed - and I find it to be too much trouble to bother with.
The default "color schemes" are yellow for (something like) the hottest 15% of the view or red for (something like) 5% of the view, or white hot, or black hot.

I can't imagine these units commanding much on the used market, and I kept mine because it is such a useful viewer. Simple too. A child can learn it in a couple minutes and actually use the thing. If they screw up the settings, they can turn it off and back on, and they are good to go.  This is the camera I fix stuff with and toss in the car and don't worry much about being stolen.

My Trijicon would take several practice lessons in the field for anyone to learn to use it, and especially to get it back to decent operation if they imposed menu settings that were poor next time they fired it up.

For your "porpoises," I think the Seek cameras that plug into a smart phone would work great.

I have no experience with them, but I was researching the Seek Reveal/pro. From the reviews this may suit your needs.

+1 on the Seek Reveal Pro or Fast Frame. Solid built and easy to use, as well as low priced.

I ended up purchasing the Flir TG130. Not the best on the market but I think it'll get the job done. I was going to hop on the Flir One gen 3 but a lot of negative reviews saying you have to connect to internet every time you use it which kind of swayed me away. I can see why Flir is doing it due to the ITAR issues and the fact that ISIS fighters have been using Flir products to fight our troops and coalition forces in the dark.