The first symptoms are a “pins and needles” sensation followed by numbness. There may be an early throbbing or aching, but later on the affected part becomes insensate (feels like a “block of wood”).
Frostbitten skin is hard, pale, cold, and has no feeling. When skin has thawed out, it becomes red and painful (early frostbite). With more severe frostbite, the skin may appear white and numb (tissue has started to freeze).
Very severe frostbite may cause blisters, gangrene (blackened, dead tissue), and damage to deep structures such as tendons, muscles, nerves, and bone.