Here's a tip one will rarely need ... but can be very frustrating if you're ever caught up in it.
We toured the Eastern U.S. once in August .... never again!!!
We had a night once where the temp was only in the very low 80's. The humidity was also absurdly high. We of course had to run the A/C full bore because of the humidity. Now ... how to keep from freezing to death? We plugged in an electric heater and ran it at the same time as the A/C. We carefully modulated the A/C setting and heater setting until we finally wound up with an interior temp of about 72 degrees along with bearable humidity. It was kindof an emergency dehumidifier.
2005 E450 Itasca 24V Class C