During hibernation, a hedgehog’s body temperature drops to approximately 4°C. That is a dramatic fall from its normal body temperature of roughly 30–35°C and helps the animal conserve energy when cold weather makes food scarce.
Hedgehogs prepare for winter by eating heavily and building fat reserves. Once hibernation begins, their metabolism slows, their heart rate drops, and breathing becomes extremely infrequent. The animal enters repeated periods of deep torpor rather than remaining in an ordinary sleep state.
The exact temperature is not identical for every hedgehog or every species. Measurements commonly place the hibernating range around 2–5°C, making 4°C a useful approximate quiz answer. The surrounding temperature, the hedgehog’s condition, and the stage of hibernation can all affect the reading.
People sometimes confuse a hedgehog’s body temperature with the temperature that triggers hibernation. Those are different measurements: a hedgehog may begin preparing for hibernation as conditions cool, but its core body temperature falls much further once deep torpor is established. Unlike bears, hedgehogs are classic small-mammal hibernators whose body temperature approaches the freezing point.