Frostbite
It only
takes a few minutes for exposed skin to become frostbitten if the temperature
is below 20 F and the wind is blowing at 20 mph or more.
What is
Frostbite?
When outside
in the cold, your body is focused on maintaining its core temperature. To do
that, it shifts blood away from the extremities and toward the central organs
of the heart and lungs. This increases the risk of local cold injury such as
frostbite to your extremities, particularly the feet and hands, and if
uncovered, the nose, cheeks and ears on the head. We have even treated a case
of frostbite of the corneas of the eyes at one x-c ski race.
Body tissues
actually freeze when they are frostbitten. Ice crystals form in the cell,
causing physical damage and permanent changes in cell chemistry. When the ice
thaws, additional changes occur and may result in cell death.
If just the
skin surface is affected, it's known as superficial frostbite; deep frostbite
affects underlying tissues.
Preventing
Frostbite
Anyone who
is not dressed properly, is outside for too long, or gets wet in cold weather
can get frostbite. It is easier to prevent frostbite than to treat it.
Dress for
the weather, not against it. Wear light, layered clothing that
provides ventilation as well as insulation. Wear a water-repellent, breathable shell
on top.
Protect your
head, hands and feet. COVER ALL EXPOSED SKIN! A number of new face masks
specifically designed for winter athletes have come on the market in recent
years. If you prefer to have your mouth and nostrils uncovered, consider
putting moleskin or Vaseline on susceptible areas. Much of your body's heat
loss occurs through your head and extremities. Helmets specifically designed
for winter sports can protect your ears as well as your noggin, and also help
retain body warmth. Goggles protect the eyes, and are less prone to fog up than
sunglasses. Mittens are warmer than gloves. Wear wool or micro fleece socks and
boots to keep your feet warm. Don't drink or smoke before going out into the
cold. If you plan on being out in the cold for a prolonged period, don't
drink alcohol or smoke. Alcohol and nicotine cause constriction of blood
vessels and leave the skin more prone to thermal injury.
If you get
wet, go inside. Keep your skin dry. Remove wet
clothing as quickly as possible. Check yourself every half-hour or so for signs
of frostbite. If your toes, fingers, ears or other body parts feel numb, get
inside.
Hydrate! Drink plenty of fluids since hydration increases the
blood's volume, which helps prevent frostbite. Adequate hydration helps
sustain circulation
Symptoms
Numbness
Skin feels frozen
Skin appears
waxy, white, or grayish.
Frostbite is
very serious. If you suspect you have frostbite, seek medical care immediately.
Hypothermia
Hypothermia occurs when the body looses
it’s ability to keep itself warm. There are varying severities of hypothermia,
the cooler the core body temperature the more severe the hypothermia. Prolonged
exposure to cool, wet, windy environmental conditions increases the likelihood
of hypothermia.
Surprisingly, hypothermia can occur even
in moderately cool weather (up to 60ยบ F) . When spending time outdoors in
colder weather, the body generates heat to maintain core body temperature in
two ways: through exercise and by shivering, which is the primary mechanism the
body uses to generate heat. Shivering intensity is determined by the severity
and duration of cold exposure and generally occurs in the large muscles of the
trunk first.
How do you recognize the onset of
hypothermia? Look for signs of the "umbles":
- Grumbling
(personality change);
- Mumbling
(having
a hard time articulating words);
- Stumbling
(reduced
coordination in the arms and legs); and
- Fumbling
(decreased
dexterity).
To prevent hypothermia, you
should:
- Wear
a hat (Winter helmet). The most significant loss of body heat is
from the head and the body has no way to minimize heat loss in this region
of the body.
- Layer
clothing. Wear warm but breathable layers of clothing to
stay warm
- Pay
attention to shivering. Shivering is a good thing because it
produces body heat, but if it reaches severe levels, stop exercising and
head indoors.
- Keep
up the pace. Keep your exercise intensity in the cold at
moderate to high intensity to help maintain core body temperature. In
order to maintain this intensity, take numerous breaks if needed
- Bring
extra clothing. If you are exercising in a relatively remote
area (such as on a long cross-country skiing excursion) bring an extra set
of dry clothes with you.
Pay
attention to the other riders! If you notice any of these warning signs of frostbite
or hypothermia in another racer or even yourself, let one of the bike
patrollers know as quickly as possible, either by flagging down a course medic
or at the nearest aid station.
