This is my idea on a custom heat sink add-in.
I'm in no way responsible for people screwing their pres up trying to duplicate this.
Ok my **** being covered this is what I did; fist I removed the back cover (standard pre cover). next I took the battery out. then removed the black paper piece that covers the 'heatsink', carefully scraping any residue off. I then traced the heatsink on paper and transfered that to a piece of metal I had laying around from an old cd drive (its about 1/3 of a mm thick). Me being to lazy to go out to the shop and get tin snips cut it with regular scissors (hence why it looks like crap). then I taped it in place at the bottom and put the battery back in praying it wouldn't explode snapped the back cover on and started it up.
The cover now fits extra snug but under my testing of 40 minutes of tethering and downloading files to my laptop the pre didn't exceed 38c
here are the pics for the other 2000s words I missed:
If anyone would like to add there opinions to this idea I'd be glad to hear them.