April 13, 2007
Weather Advisory - 2007 Boston Marathon
The Boston Athletic Association's medical team recommends the following precautions and advice for participants in Monday's Boston Marathon:
The most up-to-date weather forecast calls for a predicted Spring storm on Monday, including heavy rains (potentially 3 to 5 inches), with the start temperatures in the mid to upper 30's. Wind will likely be East (in the face of the participants for most of the race) in the 20 to 25 mile per hour range, with gusts to as much as 50 miles per hour. This will produce a wind chill index of 25 to 30-degrees Fahrenheit.
RISKS AND RECOMMENDATIONS FOR RUNNERS PARTICIPATING IN COLD AND WET CONDITIONS:
Combined with the rain, we are concerned that predicted weather conditions will increase the runners' risks for a condition called hypothermia. As with any athletic competition, as a runner you are assuming the risks inherent with participation. It is your responsibility to be informed about the risks associated with running in the aforementioned conditions, and the risks of injury or illness will increase with these predicted conditions.
While exercising in cold weather, our bodies attempt to maintain core temperature by shunting blood away from the periphery, thus minimizing heat loss. Hypothermia sets in when the body's temperature drops below normal, starting when the body loses heat faster than heat can be generated. Heat is produced by muscle action and shivering. Very low body temperatures can be life threatening.
WARNING SIGNS OF HYPOTHERMIA:
Mild hypothermia is heralded by goose pimples and shivering as our bodies attempt to raise our metabolic rates to increase our core temperature.
Moderate hypothermia will result in muscular fatigue, poor coordination, numbness and disorientation.
Severe hypothermia can result ultimately in cardiovascular failure. Treatment of hypothermia requires prompt recognition and treatment as mild hypothermia can progress to a more severe situation if not addressed early.
WHAT TO DO IF HYPOTHERMIA SETS IN:
Runners should be removed from cold, wet, or windy conditions. Wet clothing should be removed, and rewarming commenced with warm blankets and ingestion of warm fluids. If the athlete's condition does not improve, transportation to a medical facility should be arranged. Hypothermia can occur at temperatures at, or below 45 degrees Fahrenheit, or even in higher temperatures when the weather is also wet and windy. Cold temperatures, dampness, and wind increase the risk of hypothermia for runners. Sweat cools the body quickly during cold weather running. Wind evaporates it faster.
As with so many other conditions in sports medicine, our best offense (treatment) is a good defense (preparation). Following the guidelines below will help minimize risk for cold related illness and will maximize your enjoyment and performance during the race:
PRACTICAL ADVICE FOR RACE DAY:
Be prepared prior to the race. Have extra clothing which will enable you to stay dry even before the race begins.
For the race itself, dress in layers of loose, lightweight clothing. The first layer of clothing (closest to the body) should be made of polyester or polypropylene which will "wick" sweat away from the body. Subsequent layers should be loose and breathable-fleece is a good choice. Cotton should be minimized as it can allow sweat buildup. The outer layer should be wind and water resistant, thus protecting from wind, rain, and snow. When in doubt, add the extra layer. You can always remove a layer if you warm up, but you will regret not having it if you start freezing with several miles to go.
Protect your head and extremities. Wearing a hat is essential as up to 50% of body heat can be lost though the head. Gloves are important to prevent exposure to the hands. These, too, can be removed if you get warm, but you'll regret not having them if needed. Mittens are better on colder days as they will keep the hands even warmer. Shield the face with a scarf or high collar. Wear socks that retain heat and wick moisture away.
Runners with exercise-induced bronchospasm should attempt to warm air such as through a scarf or mask. A prolonged warm-up prior to hard running can help minimize symptoms. Carry your inhaler if you use one, and use it should it become necessary.
Stay with your normal hydration regime, remembering not to over drink. Do not drink alcohol the night before the race. Alcohol will make the body lose heat faster.
Run with a partner. It is sometimes difficult to recognize if you are becoming hypothermic. A running partner can help if you get into trouble. Shivering is a sign of hypothermia. The cessation of shivering may indicate more severe hypothermia and the runner should seek evaluation at a shelter.
Consider canceling your run or seek shelter if the weather conditions are too severe or you are too tired. Running on ice or over snow-covered terrain can lead to tripping, falling, or injury.
Medical stations and American Red Cross locations - located every mile along the route - along the course will have buses to handle your medical needs. Rewarming will be difficult given the weather and normal field size, so if you are not feeling well, do not wait to seek medical attention.
Help each other. Be aware of yourself but also make medical team members aware if you see someone on the route who you believe may be starting to suffer from the onset of hypothermia.
TREATMENT OF HYPOTHERMIA
Keep the runner dry and cover with blankets.
Shelter the runner from wind and water.
Provide heat to the neck, underarms, and groin. Heat only the trunk initially to avoid core temperature after-drop. After-drop occurs in this manner: Extremities cool faster than the trunk. If you re-warm the extremities, their colder blood will re-enter the circulation and actually worsen hypothermia temporarily.
Keep the runner lying down, but only in a warm dry location.
Administer warm fluids by mouth if the runner is shivering. If the shivering reflex is lost, a bear hugger should be utilized (loss of the shivering reflex signifies significant hypothermia).
Avoid moving/jarring the runner suddenly because this may trigger an abnormal heart rhythm.
If CPR is necessary, resuscitation should not be stopped until the person's body temperature is at least 95°F/35°C (never give up your efforts). All temperatures indicated are rectal measures, which give a closer indication of core temperature. If the victim is cooperative, you may take temperature by other methods.