Posted on March 19, 2010 to AOC Physician Articles
Dr. Clayton G. Lane
Here in South Alabama athletes have the advantage of being able to train outdoors year-round thanks to our subtropical climate. The downside of that is that in mid to late summer the heat and humidity can combine to put athletes at risk of heat-stroke, a deadly condition responsible for the deaths of 37 football players between the years of 1980 and 2001. While a sports medicine orthopedist’s primary job is to evaluate and treat orthopedic injuries, one of the most common issues I run into on the sideline is heat-illness.
There are three categories of heat-illness in order of increasing severity: heat cramps, heat exhaustion, and heat stroke. Heat cramps presents as cramps in the arms and legs during exertion. The athlete’s skin will be pale and wet with sweat. The athlete should be moved to the shade and hydration with cold sports drinks initiated.
Heat exhaustion, the next step on the ladder, is characterized by headaches, weakness, and “feeling faint”. The skin is still pale, but sweat volume decreases. The skin can be described as “cold and clammy” (moist to the touch). Again the athlete should be moved to the shade, but more aggressive cooling should begin such as ice bags in the armpits and groin. The athlete should lie down and remove their clothes (particularly heavy gear such as football pads).
The first sign of heat- stroke, the final stage of heat-illness, is confusion. This may be accompanied by nausea and vomiting. The skin will be red and hot. The athlete may still be sweating, but as the severity increases, sweating may stop. The core body temperature will rise to greater than 104˚F. This is an emergency. IV fluid hydration must be begun urgently and the athlete transported to the nearest hospital. During transport, the cooling methods mentioned above such as ice bags and ice water immersion should be performed if possible.
Heat illness, once it begins, is hard to reverse without discontinuing play. Therefore, coaches, trainers and athletes should place adequate emphasis on prevention to avoid not only the risks of heat-illness but also the inconvenience of having to stop a workout or withdraw from competition. Regarding weather, the temperature and the humidity are important. For example, while it may be safe to compete in 90˚ weather when the humidity is 40%, it is recommended by sports medicine organizations that play or practice be cancelled if the temperature is 90˚ and the humidity 80%. Now this is not always realistic here in South Alabama as we probably could not get through a season if that guideline was followed strictly. However, measures can be taken such as scheduling work-outs and games in early morning or late evening in the hottest months and moving to the air-conditioned weight-room or gymnasium to work-out when exceedingly hot and humid. A single layer of light-colored clothing is preferred when heat is an issue to promote evaporation of sweat and protect from UV rays. Also changing out of a sweat-soaked garment during exertion is helpful when possible.
Another means of prevention is paying close attention to athlete hydration. While body types and metabolism will vary the required amounts of fluid, a good rule of thumb is to drink 20 ounces 2 hours before exercise. Drink another 10 ounces 20 minutes before exercise and then 10 ounces every 20 minutes during exercise. Sports drinks are superior to water if exercise lasts greater than 1 hour. A good way of monitoring this is pre- and post-practice weigh-ins. If the athlete loses greater 3% body weight during exercise, they are not adequately hydrating.
Taking these precautions will help prevent heat-illness will likely improve performance.