My laptop had been having an overheating problem that wasn't obvious was a heat problem for months. I just started noticing that doing something intensive, yes like compiling the kernel, would cause the CPU MHz listed in /proc/cpuinfo to drop down, sensors listed the temperature going up, but it wasn't obvious what the range or limit was. In the end I went to replace the thermal paste on the CPU, but only got as far as removing the fan and seeing a huge buildup mat of dust and fiber blocking the heat-pipe fins. I removed that and the issue went away. There just isn't any way to see the area what was blocked until the fan was removed, and the rest of the system looked dust free, at least nothing to make me think there was a problem. If you're still reading this Moxie Marlinspike, you might want to check to see if your solution is as easy as mine.