The Arctic fox can withstand polar winters, surviving long periods below -20 °C (-4 °F), thanks to some incredible adaptations.
One of the most distinctive is its fluffy coat, which changes colour from brown to white and grows longer for the bleakest season. In certain areas it can double in length; on its underside the longer fur helps insulate the fox from the cold ground when it sits or lies down and even the soles of its feet are furry.