When and where we travel we find that the primary problem is humidity. On a hot day in Florida when Ginny decides to cook the temperature and humidity can quickly climb.
When this occurs we find that our 5000 BTU AC unit quickly removes enough humidity to make the trailer comfortable. Though comfortable, it takes more than an hour to bring the temperature down to a cool level.
We do use a small fan to blow the AC output around the trailer. We have not done anything to improve the vents or windows