Ditto, I've been bush-hogging with my 2210 in stuff taller then me on the tractor, all kinds of stuff stuck to the grill and no overheating. I DID stop occasionally to clean off the grill but only because it seemed like the right thing to do, and not due to any warning lights.
Never had a problem when mowing grass. Why is all that stuff flying up and sticking? Could it be the deck is clogged and grass is coming out the front instead of the chute?