Paul I have lived in a couple of countries that make your part of the states look like the chilly north. When you get that much heat all the time you get used to it and don't mind it as much. When you do live up north and drive down into the heat of the South in the summer you really can tell the difference. Living in Maryland we get a little of all the weather patterns, hot/cold, dry/wet, etc. So we never get used to anything and we feel all the effects of the weather. I am sitting here watching the storm that you just sent our way, heavy rain and wind but no tornados. Bill is going to come our way this weekend. Most of the energy from these storms is done with by the time they reach us.
One thing I will say about taping down foil insulation is that it would be a pain to take it back up in the spring and fall and put it down again in the summer. Some times the extra heat coming up from the floor on the passengers side keeps my wife warm while I prefer the cooler air in the off seasons.