Have you considered putting it inside cardboard box? Not covered mind you but tall enough to protect the sides. Not a tight fit but just enough to have an inch space on all sides. Not sure about it, just a thought.
I have it surrounded with the brinsea dividers and also I put a towel across the top this time. I lost power yesterday so, I hurried to keep everything warm. Luckily, I lost two degrees in my incubators; that's all.
I will tell you it is holding the humidity though. I can't get it to 65 wants to be at 70%.