When a turtle is under Brumation, its rate of metabolism slows down drastically and it completely stops moving. So to say them apart from a dead turtle becomes a task in itself. There are certain conditions you can check for to see if your turtle is actually hibernating or dead. A dead turtle will have a rotten and shriveled shell and skin, deep sunken eyes, cold to touch, will emanate bad odor, and most likely be covered in flies or maggots or floating in the tank if dead for more than a day in the water. Brumating turtles, on the other hand, are cold to the touch but they respond to external stimulation and their skin appearance remains normal.