Arctic Ground Squirrels Drop Near Freezing

In the far north, winter is not just cold, it is prolonged energy scarcity. Arctic ground squirrels cope by almost switching off their internal thermostat. During hibernation, body temperature can fall close to the freezing point.\n\nThis is possible because metabolism slows dramatically. Heart rate and breathing drop and energy use becomes minimal. Yet delicate tuning is needed to prevent tissue damage, especially in the brain, which must keep functioning in the cold.\n\nA surprising detail is the periodic warm-up. Brief rewarming bouts help perform maintenance, clear waste, and restore balance. It is not total shutdown, but a smart power-saving mode.\n\nThis resilience also inspires medicine and biology. Protecting tissues in extreme cold offers clues for organ storage and hypothermia research. Nature delivers an energy-management lesson that works under harsh conditions.