Hot tranny?

[Jim Wright]

Last night while working on the car, I noticed that the transmission was
unusually warm compared to the rest of the car.  The car hadn't been driven
for about 2 hours, outside temp was roughly 87, engine was barely warm, oil
pan had some heat, but the transmission felt much warmer than any other
part.

Does the transmission just retain heat better than other parts, or should I
be worried that there's some problem here?  I've had no fluid leaks, the
casing is relatively clean, shifting has felt normal.