Get Outdoors - Prevention: Prevent Frostbite

Prevention is no more important for any other area of outdoor health than for frostbite. Proper clothing and behaviors are essential to keep body parts from cooling and freezing.What is frostbite?

Frostbite is an injury caused by the actual freezing of tissues. Once temperature of the hand or foot drops to 59^o F (15^oC), the blood vessels maximally constrict and minimal blood flow occurs.

Factors that predispose a person to frostbite: poor circulation (caused by previous cold injuries, tobacco use, alcohol ingestion, diseases of the blood vessels, constricting garments, poorly fitted boots, old age) and extremes of cold exposure.
Windchill contributes markedly to frostbite risk. For instance, at an air temperature of 20^o F (minus 6^o C), a 45 mph wind causes the same rate of heat loss as a 2 mph breeze at an air temperature of minus 22^o F (approximately minus 30^o C).
Furthermore, since a human in motion creates his own wind (e.g., riding a snowmobile), the risk for frostbite for such a person increases.

How do I prevent frostbite?

Dress to maintain body warmth.

Wear adequate properly fitted clothing, particularly boots that can accommodate a pair of polypropylene socks and at least one pair of wool socks without cramping the toes or wrinkling the socks.
Cover the hands, feet, and face (particularly the nose and ears).
Wear mittens in preference to gloves, to decrease the surface area available for heat loss from the fingers.
Carry pocket, hand, and/or foot warmers and use them properly: fuel burning warmers or chemical packs, reusable sodium acetate thermal packs, or air-activated, single-use hand and pocket warmers.

Keep clothing dry. Avoid perspiring during extremely cold weather.
Do not touch bare metal with bare skin. Cover all metal handles with cloth, tape, or leather. For brief periods of exposure where dexterity is required (such as cooking), wear silk or rayon gloves.

Certain liquids (such as gasoline) become colder than frozen water before they freeze, and can cause frostbite.

Move around. Do not maintain one position in the cold for a prolonged period of time. Avoid cramped quarters.
Wear a sunscreen with a cream or grease base to prevent windburn.
Stay well hydrated, well fed and well rested. Eat enough food to maximize body heat production. Avoid becoming fatigued.
Do not "overwash" exposed skin in freezing weather. The natural oils are a barrier to cold injury. Shave sparingly or not at all. If skin becomes exceedingly dry, apply a thin layer of petrolatum-based ointment.
Do not drink alcohol or use tobacco products.
Keep fingernails and toenails properly trimmed.
Do not climb during extreme weather conditions.