I hadn't experienced this in a long time at this point but tragedy is back: I pulled my SP4 out of my bag super hot. I'd guess that it was around 70 degrees, very uncomfortable to hold and the heat radiating out of my bag. It wasn't obvious when I took it out of sleep what was causing this in Task Manager. No idea if this is just a continuation of the old bug or whether it's a new one (since I haven't experienced this in at least a month). Looking at the battery report, it turned itself back on immediately after I put it to sleep and put it in my bag and stayed awake for the next 2 hours, burning through 50% of my battery (96% -> 46%). I'm starting to lose confidence that Microsoft can make a consistently competent product. I was so hopefully this time after the past month's basically perfect performance. I just hope nothing was damaged as it stewed in my bag.