Your fridge in the caravan or motothome is invaluable in this scorching weather. Do remember that if your fridge has its vents on the awning side then make sure you do leave a good amount of air flow into the awning.
Try an angle the caravan or motorhome so that your vents are not directly in the sun or use a second parasol to shield the vents from direct sun.
Your fridge needs to be level to work.
If the temperature is exceeding 25degrees then you will need to remove the vents completely allowing uninterrupted air to the back of the fridge.
The fridge should work to 5-8 degrees when the temperature is 25 degrees. Any hotter and the fridge will not be as cold so be aware!.
Opening the fridge too many times will also make the fridge not work as well. Try to move some cold items like drinks to a cool box so that you don't have to keep opening the fridge when its really hot!.