As far as I know from my own experiments with cheapo thermal imaging (I had a Seek Thermal camera for my smartphone for a while. It was pretty neat, and worked well enough for short distances), the only decent way to evade thermal imaging is to either have a lot of insulation between you and the camera, or a pane of glass.
Glass reflects thermal IR pretty well, although I’m sure with sensitive enough cameras, they’d be able to see through it. Plus, a big shiny mirror is kind of conspicuous when it’s not sitting mounted in a wall, but instead is a moving patch of bright reflectivity.
