Caused by freezing conditions which cut off circulation, usually in extremities (hands, feet, ears, nose), which may be permanently affected. Frost-bitten areas are cold, pale or marbled-looking, solid to the touch, and painless (until circulation is restored). Most at risk are people who already have circulation problems and people taking beta-blockers to lower blood pressure. If deep tissues are damaged, gangrene may set in.
First aid consists of moving the casually to shelter, giving warm drinks, and covering with blankets. Warm the injured part with body heat only-put a hand under an armpit, for example. Do not rub the skin or apply direct heat to the injured area. There will be redness and considerable pain as the affected part thaws. Keep the casualty warm, and get him or her to hospital.