Skin sores or bumps that happen after exposure to very cold temperatures.

Chilblains (CHILL-blayns) is a condition that causes inflamed swollen patches and blistering on the hands and feet. The exact cause is unknown. Chilblains may be an unusual reaction caused by the small blood vessels expanding more quickly than the nearby larger blood vessels can handle. Women, underweight people and people with Raynaud's phenomenon are at increased risk.

Common symptoms include small, itchy areas, most often on the hands and feet. Other symptoms include sores or blistering, swelling, pain, and changes in skin color.

Self-care treatment for chilblains includes keeping the hands and feet warm and dry. The skin usually clears up on its own within 1 to 3 weeks, though it may recur each cold season for years. If the condition doesn't clear up with self-care, medicines to treat the skin or improve blood flow may help.