[Will]

If you're feeling especially brave, you can unplug everything on the system board, put it in your dishwasher and run it. That cleans out the dust really well, and as long as it is dried before you try plugging everything back in, works fine. Although it's probably not a good idea if you have hard water...

With the canned air, it may be hard to get some dust cleared away, especially on heat sinks, especially on the CPU. You should be able to remove the fan from the heat sink (usually there's some locking levers and some clips) to get better access, and if that still doesn't work with the compressed air, take a damp (meaning, not dripping) napkin and wipe away the dust.

And while the temperature is that high, it's probably a good idea to only have the computer on when you really need it, and maybe keep the side of the case off for better air flow.