You don't need to run your heat in the winter either, I take it? ;)
I love my Mac Pro 3,1 (2 quad Xeons, 3 SSDs, 2HDDS, 2 optical drives, 16GB RAM...), but boy is it ever unbearable to sit near in the summer months... Thinking I might scale down once this one gives up the ghost... Which is a shame, my computer graveyard is full of Apple towers - G3, G4, and G5. Other than that, I haven't owned a laptop since my first-gen MacBook (Core Duo), and that thing was a piece of crap. I don't think the original Core processors were great, and the transition to Intel and new hardware brought with it some expected snags, but that machine and I had some fights. But I did manage to run both FCP and Avid on it, and it got me through school as my secondary machine, and still technically runs so... Can't complain too much!
Actually my Mac Pro 4,1 doesn't overheat at all... they're not supposed to, your 3,1... maybe your fan is broken, or add cooling agent?
And yeah, the tower Mac Pro's are a classic! Glad to find someone here with another one.. I wish I could afford the new one that looks like Darth Vader..