I currently have Kali 1.0.5 x64 running from a USB drive. This was made using UNetbootin and has worked well for the most part.
One main issue I keep experiencing however, is the machine that is running Kali from the USB tends to heat up quickly and the fans consistently stay loud.

So far I have tried this on 4 physical machines - 2 AMD/ATI laptops, 1 x Intel/NVIDIA laptop and 1 x Intel/NVIDIA desktop machine. I have been able to confirm that all 4 of the machines I have tried have the same noise/heat issues.

What I want to know is, does this in any way relate to drivers that I'm lacking and that once these are installed everything should run well, or is Kali lacking support for certain functions that is causing this issue?

Running Kali as a Live environment tends to complicate the drive installation issues but this can be solved with a separate hard drive so it's not a major drawback. What I'm having difficulty understanding is, why I don't experience this same thing with BT5 R3?

Any help or advice is appreciated.