My box turtle won't move or eat. Is it sick, dead, or hibernating?

I am sorry to hear about Nokta. I too, am worried about what you describe. Although when they hibernate their limbs are usually in the shell, not out. I do worry that she could be gravely ill and very weak. It can be hard to tell if a turtle is deceased. It is impossible to find a heartbeat, and reptiles can survive on only breathing very infrequently. I would recommend having her evaluated by your veterinarian as soon as possible. If that is not available then try to warm her up and see if she will
Move. If she is alive she likely needs veterinary care to survive. Best of luck and thank you for using Pet Coach.