Earlier this year a group of Rovers ran Hole in the Rock in Utah. It was pretty warm, highs in the mid 90's I think. We had Disco's, Rangies, and Defenders. All of the Defenders were running pretty hot, not boilover but for sure on the extreme high end of safe. The Disco's and Rangie were Ok even with AC running part of the time.
I would be afraid if I restricted airflow across my radiator with a protective grill small enough to stop sticks etc., it might do more harm than good.
The democracy will cease to exist when you take away from those who are willing to work and give to those who would not. -Thomas Jefferson