Animals that hibernate lower their body activity sufficiently to enable them to survive for the dormant period without food. This requires a cold environment to reduce total body energy requirements. Global warming will require hibernating species to relocate to find the optimum temperature environment to maintain appropriate energy expenditure levels. Humphries et al (2002) use a bioenergetic model to show that the optimal hibernation zone for the little brown bat will move northward by approximately 350 km over the next 80 years due to global warming.
Humphries, M. M., D. W. Thomas, and J. R. Speakman, 2002: Climate-mediated energetic constraints on the distribution of hibernating mammals. Nature, 418, 313-316.