Wednesday, December 30, 2020

Keeping Your Cool in the Cold


'Tis the season for fat-bikes, snowshoes, and skis, but before you slide into the Winter Wilderness, remember, "There is now such thing as bad weather, just poor clothing choices."

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.