cardboard or kids foam play mats in various pieces. im in texas and have this issue all the time. it never gets hot, and i don't mean the heater core, the engine temp. i have an aftermarket temp gauge in place of the factory one and it gets to about 140 when i get to work, and thats letting it warm up outside, taking the kids to school, coming back home, then going to work. it just doesn't get hot, unless its summer with the a/c on and im sitting in traffic, then it gets hot and i have to increase rpm to spin the fan (body lift) to get it to cool properly, and thats with an electric fan helping......feast or fammin with this i guess. but the best thing so far is a piece of cardboard with a lip thats bent over the top of the radiator to help keep it in place, i think i use a piece about 18" wide to cover up at least half of the radiator. its free and plentiful.