I usually am rolling in the summer and store the rig in the winter so haven't had any heat issues but here are a few suggestions. First put something down under the tires, like plywood, so they are not directly on the cement. Then put a good cover on the tires. I would not use a RV cover because that will just seal in all the heat and humidity. You will most likely turn the battery disconnect to off, if not the battery will just die anyway, so the fantastic fans, if you have them, will stay in the open position and if it rains water may get in so I would leave all fans closed and just crack open a couple of windows to allow for ventilation. If possible have someone nearby go once a week to check on things if that is an option. If you have a generator they should run it at least once a month. This will help keep the battery charged.