I've played around with daydream enough and every time i use it even if it's 10-15mins indeed it does get hot. If i play a game on it that is not VR the phone does not get hot almost as if i'm not even using it, but if i use the daydream head set to play a VR game it does get noticeably hot, however I have not had a shutdown yet then again I don't seem to use it for more then 20 mins at a time. Mostly to test out games and show friends. I do notice that battery drains much faster and based on reviews all of this is normal.