Hibernation is an adaptive behavior for some small animals to survive cold winter. Hibernating mammals usually down-regulate their body temperature from ~37℃ to only a few degrees. During the evolution, mammalian hibernators have inherited unique strategies to survive extreme conditions that may lead to disease or death in humans and other non-hibernators. Hibernating mammals can not only tolerant deep hypothermia, hypoxia and anoxia, but also protect them against osteoporosis, muscle atrophy, heart arrhythmia and ischemia-reperfusion injury. Finding the molecular and regulatory mechanisms underlying these adaptations will provide novel ideas for treating related human diseases.