Is it possible to downgrade the kernel (oneiric) to the version used by 10.10?
Seeing that your mean reason is overheating, I'd suggest installing Precise Pangolin A1.
It is the current development version, but seeing it's for an LTS version it will mainly see bug fixes and ironing out the flaws. I've heard from reliable people that the A1 (or Alpha 1) is seeing great improvements in terms of power management.
You can also check out this Google-search: power management ubuntu 12.04
Downgrade: How to downgrade the Kernel on 11.10
Note: At here, with the 10.10 kernel, network connection wasn't working.
Upgrade: How can I upgrade kernel to 3.1?
Note: The Precise kernel is now 3.2.