Well, I've left it running a game flat out (throttle off, 0 frameskip) with fullscreen HLSL and the GPU temp doesn't seem to go above 60 degrees. This GeForce GTX 750 Ti comes with a GPU monitoring/overclocking tool which the manual says not to let the GPU go above 90 degrees, so I'm still way short of that. Running the game a normal 100% speed, the temp barely goes above 30 degrees.
I'm pretty sure the throttling issue you experienced is simply due to laptop onboard GPUs being pretty weak (by comparison) and so have to work that much harder. Coupled with the fact they have limited cooling.
I wouldn't expect to have such problems with a desktop PC. Well, not running MAME, anyway.