My friend i dont think so that its a battery sensor problem, because i have replaced four batteries but the problem is same it still give the same message "Low Temperature crap" and when i restart the phone wont turn on.
and than to turn it on again i have to open the back cover and press the bettery connector and power button than it gets on. (and i have to do it 4 to 5 time than only its on, sometimes iam lucky, so it gets on in first attempt only.
please guide me if u have a proper solution for this, mine is also D800 same as urs.
Thanks a ton
Altamas