Transmission Heat

I have a '99 auto, and after driving for a while I can feel heat coming through the E-brake location. I don't have a transmission cooler & I fear that I am destroying the transmission by allowing it to get so hot. The car has 45K miles & had a transmission flush at about 25-30K miles.

Does anyone else notice this in their mustangs?

I don't believe I have any symptoms of a transmission going bad, but what would be the warning signs?

Are my 4.10's contributing to the excess heat?
 
Dynamat that and drop either extremeliner or dynapad on top of that and no more heat problems. I would do like the other poster suggested and buy the cooler otherwise your treating the result rather than the sympton.