The first time we went camping in our new trailer it was well into the upper 90's. When we went to bed I was happy to have the 2nd A/C unit in the bedroom. The Thermometer I put in there said it was a chilly 65 degrees in the bedroom when we went to bed. But we were warm, too warm. The next night I put a thermal prob down into the pass through and while it was 65 degrees in our bedroom, it was 80 degrees in the pass through and the heat was rising up through the plywood and the mattress and warming us like a waterbed!
So this weekend I took a couple sheets of Foam insulation and applied them to the bottom of the bed, the sides of the under bed storage and under sideboards. In doing so I found a couple of good sized holes where I'm sure warm air (and who knows what else) could pass through. That's all plugged now. Hopefully this will help. We'll find out soon enough.