Having said that I've had this model for quite a while now and have been doing this since I can remember and never had this issue until the latest macOS update, which from what I've researched seems to be affecting loads of people with all sorts of newer, much fancier processors than what I have.

While I will definitely keep your advice in mind going forward, it seems that this issue sprung up only after this last update, which is strange because I remember reading something about "improved energy management" or some such.

Regardless, I'm still unsure how it can read these temperatures since the "put in freezer for a while" method seems to work when it does this and everything gets "un-sluggish" right away and starts working as well as if I restart it, no matter how many things are open.

So it's like the processor "works as if it wasn't overheating", but for some reason the temperature readings for things like synching sometimes don't work because it reads the temp as approaching ~200º, and even external apps read it as such (though I realize they may just be repeating an internal OS error).

Just not sure how the processor definitely works very smooth, very fast, just like as if I restarted it whenever I take it out of the fridge, but the sensor is somehow reading ~200º.