it’s the reverse. the ceiling and the walls heat up and heat the inside more than your griddle. more surface area collecting heat. First I did nothing, couldnt stand it. then insulated and it helped but still sweltering, then I painted the ‘white” reflective roof coating and WOW, what a difference. I also have a custom made griddle cover that I use in the summer which accounts for getting out 90% of the griddle heat from inside straight through the wall. Just think about how hot the inside of a car is during the summer. It WILL be that bad and worse without it. We all deal with the heat, it’s called CDOB, Cost of Doing Business. If you do not plan to install an AC, you better be pushing some major cross ventilation.