I have home-made a removable awning that clips to the top corners of the slide containing the fridge. Some shade-sail material, "S" hooks, parachute cord and tent stakes.
I have slide toppers, so I put shackles on the topper frame at both ends of the slide where I can hook the top edge of the sail (with some cord on both ends to center it in front of the fridge vents). The bottom corners are held away from the trailer with tent stakes; sorta like a lean-to.
I'll admit it looks a little trashy, but just that little bit of shade made a BIG difference on fridge performance when we were in the desert Southwest in June and July where we had 29 straight days above 105 in the afternoons.
I always tried to get a site where the driver's side (fridge side) if the trailer was facing East or North, but when that was not possible, I deployed the shade-sail. Nobody ever objected.
I plan to carry it from now on.
P.S. I installed 2 High efficiency fans with thermostat control (replacing the factory fans and thermistor) just below the bottom edge of the top vent opening right after we got the trailer. They run whenever the temperature in the "chimney" area gets above 98, They run a lot.