The term 'BEAR'S HIBERNATION SPOT' can be solved by the three-letter word 'DEN'. A DEN is a shelter or refuge, typically a small cave or hole in the ground, which is used by animals such as bears for hibernation. Bears usually hibernate during the winter months, when food is scarce and temperatures are low. During hibernation, bears enter a state of deep sleep, during which their heart rate and breathing slow down significantly. They remain in this state until spring, when they emerge from their dens to search for food.