Chilblains, also calle perniosis or blain, when occurring on the feet, is a medical condition that is often confused with frostbite and trench foot. Chilblains are acral ulcers that occur when a predisposed individual is exposed to cold and humidity. Acral refers to the extremities (e.g. fingers and toes). Chilblains are often idiopathic in origin but can be manifestations of serious medical conditions that need to be investigated. Chilblains can be prevented by keeping the feet and hands warm in cold weather. Smoking cessation and consultation with a dermatologist is advised.