Blanket thermal imaging or thermal imaging without other probable cause has been ruled unconstitutional in the United States. Police cannot fly around with thermal imaging cameras looking for grow houses. They also cannot drive around your neighborhood looking for your grow room with thermal imaging cameras.

A small personal grow will likely not be discovered by thermal imaging alone. Police will likely discover or fabricate some other evidence before using the thermal imaging equipment to locate your grow.

Nonetheless I remain fearful of this equipment. Worm's Way stores have thermal imaging blocking material available. It is expensive, but if it provides some peace of mind it is worth it.