I took the heat sync and fan off of the processor and blew it out. There was a lot of dust! In addition I thinned the layer of thermal paste on the processor. I also turned the fan speeds of the back and top fans from medium up to high, and the front fan's speed from low up to medium. I encoded a video with no grief from my computer's internal speaker, however I haven't put the side panel back on yet, so that could have something to do with it.
I won't worry as much anymore, though, because now know that the computer would shut off before any real damage is done. That is comforting. (I must protect my precious baby!)