lol @ Stworca,
hmm... ODing on a nice natural substance like fresh air doesn't seem half bad..
it had indeed been a long while since the comp was cleaned out....
Amidst the chaos I ended up neglecting to do so, but was forcibly reminded when it began shutting itself off. I used RivaTuner to increase my fan speed from the Nvidia default 60, and upped it to 100. That helped considerably in the interim... and now with a nice clean inside as well.. the improvement is huge.
Luckily I don't smoke! Good lord.. why would anybody keep their computer in their coal fired boiler room?
(suddenly I don't feel so bad)