Biomechanics

By Amanda Brunner

Frostbite and Hypothermia

The weather is beginning to change from temperate fall days to colder winter ones. Don't let this weather discourage you from riding, but do take precautions so you don't wind up with frostbite or hypothermia.

Frostbite and hypothermia are the result of prolonged exposure to the cold, and often cases result from short exposure to extreme cold. Our body’s ability to limit heat loss and generate its own heat can be easily overpowered so it is up to us to assist in the process.

Before going on a ride you should layer clothing and definitely wear a hat or bandana under the helmet due to the fact that most of out heat loss is lost though the head. Eat a well balanced meal and drink plenty of fluids. When you start to feel tired take a break and even if you don’t feel thirsty, be sure to drink water. Working too hard can result in sweating. Normally this is a good thing as it quickly dissipates body heat through evaporation but wet clothing in cold weather is the formula for disaster. In addition to the fact that excessive sweating catches up once you stop doing your activity by cooling you down too quickly. Try to refrain from alcoholic beverages and caffeine.

Our body uses two mechanisms to heat up. It uses its core (internal organs including the brain and the heart) and it uses the shell which includes muscles, skin, and limbs.

Hypothermia occurs when the core becomes injured by the cold. Hypothermia sets in when the core body temperature dips below 95 degrees Fahrenheit. The first signs and symptoms that occur include: uncontrollable shivering, change in mental status, unconsciousness, cool abdomen, and naturally a low core temperature. Some of the more severe signs will include irregular heart and respiratory rates, rigid muscles, and dark and puffy skin. Should you encounter a fellow rider showing these signs and symptoms get medical attention immediately. Remove the person from the cold, remove any wet clothing and replace with warm, dry clothing, add insulation such as blankets or towels. Ensure that the person is lying flat on their back and try not to move them that much as it could result in them going into cardiac arrest. You may have to administer CPR until further help arrives. Make certain that you don't warm the person too quickly and avoid massaging the muscles for heat as this could result in sever tissue damage if done incorrectly. Also never administer alcohol or nicotine products in attempt to speed the warming process.

Frostbite occurs when the bodies shell becomes injured due to the cold. Frostbite's severity is usually characterized into four phases. The first step is superficial: The blood vessels constrict resulting in inadequate blood supply to that extremity. Symptoms look like white or grayish-yellow waxy patches on the affected surface. The sufferer usually feels numbness and icy cold in that extremity. The second phase occurs when the skin temperature drops below 24 degrees Fahrenheit as ice crystals literally start to form in the tissues. This usually looks like little blisters on the skin. This needs to be addressed immediately or the third and forth stages are likely to follow and are very dangerous. The third stage happens when fluid leaks from the blood vessels into the damaged tissue. The blood vessels then clot resulting in irreversible damage to the affected tissue. The blisters which were once a yellowish color in the first two stages now become a dark purple color (which is indication of the fourth and final phase of frostbite damage). The fourth stage usually winds up in amputation of the extremity.

When frost bite first starts to occur take the sufferer inside to a warm area, remove any constrictive clothing, replace wet clothing with dry warm clothing. Place dry gauze between toes and fingers if they are affected so that moisture can be removed while preventing the tissue from sticking to one another. Slightly elevate the affected area to reduce any pain. If frostbite looks severe get medical attention immediately and don't try to re-warm on your own. If you are certain the damage is superficial, attempt to re-warm by placing the affected area in warm NOT HOT water (approximately 102 to 106 degrees Fahrenheit). This process can take twenty to forty minutes and should be performed until the tissue is soft again. Even if it is superficial frostbite you may still want to be checked out by a medical physician as soon as possible to rule out any further damage. Watch out for refreezing after the tissue is re-warmed because this could result in irreversible tissue/ nerve damage.

Frostbite and hypothermia can occur simultaneously so your highest priority is to take care of the hypothermia first. If you re-warm the body's shell before the core it could result in pooling of blood in the extremities resulting in cardiac arrest.

Have fun out there but be weary of the cold. Make sure to always ride with a buddy, wear warm, layered clothing, eat a nutritious meal before hand, drink plenty of water, avoid caffeine and alcohol, and take frequent rest periods so as not to break into sweat. By exercising caution this winter could be anything but an off-season as you enjoy what Mother Nature has to dish out.