So my BSOD problems have not subsided. I've been getting help elsewhere too, and the consensus at least thus far is that it's not a hardware or temperature issue. It seems to be some kind of software issue, particularly Drivers. Now I've been trying to update Drivers everywhere but it's very scattershot and nothing is taking. Going on the advice of another user, I made some Event Viewer logs for both Applications and System which have been included via a MediaFire link:
My Files. This covers the previous hour before I made the logs. Multiple BSODs occurred, some of which did not actually display a BSOD but instead simply scrambled the screen and sound. The latest of the crashes happened between 11:15pm and 11:21pm.
Again, this usually happens while I'm playing games, TF2 and Civilization 5 specifically.
Just before the latest crash, I tried eliminating one possibility by uninstalling and disabling my onboard LAN adapter because I only use a wireless USB network adapter.