12-31-2016 12:21 PM
Thanks for the reply.
I haven't performed other tests to pinpoint what the culprit is, but I highly doubt the web pages were at fault here. I use an extension "Great Suspender" which suspends inactive tabs on Google Chrome (the only browser opened during which the problem surfaced) and a few tabs that were not affected by this extension were simple, text-based pages that did next to nothing in terms of CPU usage.
I only have Windows Defender as my anti-virus program, and the programs that were running (just opened, idling) at the time include HWMonitor, a torrent client with no torrent file, and two paused videos, none of which uses much CPU according to the task manager (0.2% for HWMonitor and 0% for the other two).
However, I did discover something off on the Task Manager; there are four Windows Explorer (32 bit) tasks which comprise at least 10% of CPU usage at any given time, spiking up to 25% at whim. This has to be the reason why the fans spin and the temperature rises, though I have no idea why there are four of them and why they fluctuate so much. I'm sure they will stay there until I restart the system (sleeping did nothing).