thermal imaging works only at night so running the light during the day will solve that. an exhaust fan disapating the heat works just vent it in an area near the water heater, house heater or fireplace. Insulation, fiber glass in between the construction with 2 inch stryofoam panels over it will block most of the heat transfer. remember nothing is perfect , nothing. most busts are from someone with a big mouth so tell no one you are growing, trust no one. if you could hide a cow then you could grow safely, hiding a cow also means hiding the food , water, waste and sounds, there's never a perfect way, it's what you can live with with out the worrying. It takes a while to be comfortable if ever. good luck
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