Chilblains is an uncommon medical condition where the foot develops ulcer-like looking sores and the toes may turn blue or have a blue mark underneath them. It usually shows up in the winter when the weather is cold and moist. Chilblains is a painful condition and may affect the fingers, ears, nose, buttocks, or thighs. It shows up after being exposed to the cold for several hours. Cause No one knows why some people develop chilblains after exposure to the cold while others don’t. The condition is most often seen in thin or underweight women. Treatment and Prevention The sores usually resolve themselves, taking anywhere from a few days to a few months. For cushion support consider sensitive feet insoles.