I made a post in February addressing the issue of random restarting in Nokia 8. It only happened when the phone wasn't charging. It finally led me to believe that the problem was with the battery. Nokia 8 has Aluminium body and so it conducts heat better than glass or plastic. I didn't use any case in winter and my phone was really cold every morning. I finally changed a battery and brought a case made of insulating material and it's working fine now. It still restarted 3 times in last 4 months but I can live with that. I suggest using insulating cases for Metal phones. Hope you guys get your issue resolved. I hope HMD makes better insulating layers around battery.