My Samsung Note 4. Crashed after an update.

[AC Question]

My note 4 updated itself last week. It slowly deteriorated....freezing...spurious shutdowns..till Monday afternoon it just died. The phone became very hot then died......Now unable to turn on. I checked the battery...showing 3.8v.....I even tried a factory reset...nothing. 2 friends are now having similar problems.....both after upgrading their systems