Testing thermal performance is as simple as going to a restaurant down the street and asking if you can pay them $100 to borrow their walk-in fridge for an hour

Testing thermal performance is as simple as going to a restaurant down the street and asking if you can pay them $100 to borrow their walk-in fridge for an hour for cold, and leaving your device in a hot car for an hour for hot. It's also exactly the kind of thing you should be doing if you're selling an actual product to a customer instead of partnering with someone to test your prototype.