I have found a software to throttle CPU usage by limiting specific processes, and thus reduce the tendency for CPU to over-heat, which always happen to me when the game is running for a long time. Of course, when you limit CPU usage, the client might get a bit laggy, but this is fine if you are just staying in one spot for AFK or semi-AFK. Just don't throttle when you need to be active, such as raids or Colony War.
Simply start BES and click Target button to select Sword of the New World process. Click Limit This and Yes to confirm. Click Control button to specify how much you want to reduce resources allocated to this process. I usually throttle it at -50%.
See Battle Encoder Shirase for how-to-use guide and download links.
The default background is a picture of some stupid penguins. I have modified a GE wallpaper to fit the software skin. Simply download the picture here and save it as defskin.jpg in BES program folder (over-write if prompted).