Immersion hand or foot

**Definition:** Injury to the skin and soft tissues of the feet and, less commonly, the hands due to prolonged exposure to non-freezing cold and wet conditions. Originally reported in soldiers as trench foot during World War I, it is now more commonly seen in the homeless either because of vagrancy or as the result of conflict. Affected extremities are initially cold, numb, swollen and pulseless; this is followed by a period of intense hyperaemia and pain which then gives way to increased sweating and cold sensitivity.