Heck, thermal epoxy a water block to it, connect the leads to your sink, and run a cold water exchange.
Or import an elephant from Africa and surgically implant your motherboard into its left butt cheek.
Seriously, if your <i>south bridge</i> is burning up then RMA or replace the defective motherboard. Doing anything else is just plain silly. The last thing that anyone needs is a defective south bridge, and severe overheating can only be an indication of a flaw in it somewhere.
"Sad is the elephant upon the ice who went to put on his wooly coat only to realize that he left it in his other trunk." - DeEvolution