Heating Issues with an 8400M GS

My laptop graphics card, a humble 8400m gs (core clock 400mhz, memory clock 600mhz), usually operates (according to GPU-Z) at 169mhz core clock and 100mhz memory clock which usually results in a core temperature of 60-70 degrees. Recently however, I have noticed that the clocks often go up to maximum resulting in GPU temperatures of up to 90 degrees and soon after that the screen fades to black. Is there anything I can do about this?

The clock fluctuations are very recent but I can't think of any specific cause (I've restored to factory settings and the problem continues). Thanks for any advice (as I write this my laptop is sitting on bag of frozen peas).

R_N

I know this isn't as exciting a thread as a discussion relating to the merits of the GTX 260 vs hd 4870 but any help would be most appreciated!