Turning your AC down at least as low as 68 and leaving the fan on "ON" vs "Auto" will help tremendously. We were in the full sun at the coast (Port Aransas, TX) on a recent trip and this is what we had to do. It would get very cold at night but an extra blanket on the bed made for awesome sleeping conditions as well the cold trailer in the morning made it easier for the AC to keep things cooler in the afternoon. Our inside temps during the day still rose to 74 even though set at 68 but we were pleased with that. I'd rather be cold at night than miserable hot so this works for us and helps our dog when we go out somewhere that she can't go with us. We also do this when staying at one of the lakes nearby. Seems TX weather is always hot in the summer. This is why our longer trips are usually to Colorado...our escape from the heat!