How hot.
 

Is to hot for nimh batteries after a run.

I've read about when charging not to let them get above 140 deg. . Might hold true to discharge as well

Not so hot that they vent....seriously, they can get hotter than they do when charging, but I wouldn't want mine getting outside140-160F - they don't last long getting that hot (life). You do some damage everytime you get them that hot. If your setup is cooking them, time to gear it down some and see if that will make it run cooler.

If you're racing, you can push them mor ethan you would if you're bashing. I charge mine at rates that keep temps 120-130F.

mine seem to stay cool during charging and then get to about 110-120 in the last few minutes of charging.

Charging causes a reaction inside a NiMH batt that generates heat. One of the ways to be sure a NiMH is charging correctly is to see if its getting hot.

Mine do the same, show some minor temp change early, then move up gradually to 110-115F an stay there until they peak, when they'll hit 120-130F.