Dave,
Just to clarify any misconceptions abouts bears & hibernation, here are the facts:
Bears, unlike some other mammals ( woodchucks, marmots, & bats...just to name a few), are not "true" hibernators. Bears enter what can be more accurately described as periods of "deep sleep" vs. true hibernation. While bears do not urinate or defecate during these periods, and are also capable of living off of stored fat reserves, this is where the similarities with true hibernation end.
Bears maintain near normal body temperature, heartbeat & respirations while they sleep as opposed to the true hibernators. Bears also forego the altered state of consciousness that hibernating animals experience, and can easily be awakened from their winter sleep. This is why researchers doing winter den surveys of sows with cubs are required to tranquilize the adult bears prior to examination. This is also why, as noted earlier in this thread, bears can periodically be observed out of the den during the winter months if conditions are favorable, but you will NEVER see a true hibernator on the prowl once they have gone to ground for the winter.