I installed Sierra yesterday with no problems. Before going to bed I plugged the computer in to charge overnight, as I do every night. I ended up falling asleep with the computer still on, and when I woke up it was completely dead. No response when I tried to wake it up, and no response from the power key. It was very warm. I left it connected to power the rest of the night, and this morning it was in the same state. It was also still very warm. I disconnected from power and performed an SMC reset (Shift-Control-Option-Power, then Power again), and that rebooted the computer. It's running a bit sluggish, and the battery is draining very fast (already down to 95% and it's only been on for about 15 minutes). It's still a bit warm, though not as warm as it was when connected to power. It also keeps losing connection to Gmail / Gchat which I have open in another tab in Safari. Has anyone experienced similar issues? Obviously Sierra will need to index for a while, but it definitely shouldn't brick the computer and require a reset.