The system is way underpowered for this kind of material. Too slow a CPU, not enough memory, insufficent disk setup, etc.
Wow... didn't realize GoPro was that funky!
Depending on what your eventual output size is, I would recommend transcoding it first. Yeah... okay... not much help with the current project ;-) If standard resolution (640x480) is good enough for you, you can transcode the footage to dv-ntsc before you edit. Your machine will thank you for it.
Also, ice is probably not as useful as moving the air around the laptop with a fan. This is one reason I hate to edit on laptops. Whenever I even work on one, I always prop the bottom up with a stick of wood or a box to maximize air flow.