|John Glenn School Corporation|
5360B - GUIDELINES FOR PREVENTINGHEAT-RELATED PROBLEMS
Heat illnesses are due to a disturbance in the body’s mechanism of heat control. Simply by increasing physical activity, one can increase the body’s heat production by ten (10) to fifteen (15) times the resting rate of heat production.
Radiation, conduction, and convection account for sixty-five percent (65%) through seventy-five percent (75%) of body heat losses. Perspiration and evaporation account for only fifteen percent (15%) through twenty percent (20%) of heat dispersed, depending upon the air temperature and humidity.
As the air temperature approaches body temperature, less heat can be transferred by radiation, conduction, and convection. Sweating then becomes paramount to cooling. High humidity impedes evaporation, limiting the cooling potential of sweat. Thus, the result is a limited spectrum of heat-related problems with higher heat and humidity.
Athletes are at higher risk of developing heat illnesses – ranging from mild heat cramps to the catastrophic heat stroke. Preventative measures and early recognition can save lives.
|A.||Heat Cramps and Heat Syncope|
|Heat cramps strike the unconditioned athlete most commonly. In the early season, unconditioned football players develop painful cramps as a result of dehydration. Usually, the large muscles of the lower extremities are involved. Rest, fluids, and ice packs usually bring immediate relief. Exercise can be resumed at a lower rate after recovery.|
|There is no evidence that salt deficiency is the etiology of these cramps; therefore, salt tablets are unnecessary. The normal diet contains sufficient salt to replace that lost in sweat.|
|Most heat cramps are due to unaccustomed exercise in hot, humid conditions. Simply by reducing exercise over the next ten (10) through fourteen (14) days (after heat cramps develop) the body acclimatizes itself to the heat by more efficient sweating. Then a gradual increase to peak exercise can be accomplished without ever over-taxing the athlete and risking illness.|
not a dehydration problem; it is best treated by laying the participant in the shade, offering cool water or cold compresses, and loosening tight garments.
Heat syncope is the sudden fainting spell seen on hot days when one stands at attention for long periods of time. This is commonly seen at military parades or band contests. The fainting spell is due to a lowered blood pressure caused by pooling of the blood to the legs, brought on by a reflex to the heat. This is
|Heat exhaustion is the state where prolonged sweating leads to dehydration and subsequently to symptoms such as muscle weakness and cramps, fatigue and nausea, and cold, clammy skin.|
|Treatment is rest in the shade along with water. Fluid replacement usually results in rapid improvement. These individuals require more monitoring to ensure fluids are being replaced. Any vomiting is a sign that further therapy is necessary and may require intravenous fluids (IV’s).|
|When heat generation exceeds the rate of perspiration, the body temperature rises dangerously. The temperature-regulating area of the brain succumbs to the high temperatures resulting in heat stroke or neurologic abnormalities. Symptoms are hot dry skin, elevated temperature with delirium, seizures, and eventual coma. Treatment consists of cooling the body immediately with ice packs or cool water. Often large quantities of intravenous fluids are necessary.|
|Heat stroke can result in death unless treatment is initiated immediately. The longer the delay in treatment, the greater the chance for mortality. Thus, the rule - treat immediately with ice and cooling water whenever heat stroke is suspected. An ambulance can be called while cooling measures are initiated. The easiest method to cool an overheated participant is to pack ice cubes around him/her, while rubbing the skin with cool, moist compresses. Shivering is a signal to stop the cooling, in that hypothermia can result from excessive icing. Any patient exhibiting central nervous signs should be observed by a physician for heat-induced damage to the brain, heart, or kidneys.|
Once an athlete has survived an episode of heat stroke, s/he should be monitored carefully due to increased risk for development of further heat-induced illness.
|1.||Gradual conditioning two (2) through three (3) weeks before exercising at peak level-"report in shape."|
|2.||Frequent water breaks during exercise.|
|4.||Avoid exercising when heat and humidity signal dangerous conditions.|
|1.||Water load (1 quart) before exertion and drink eight (8) through sixteen (16) ounces every fifteen (15) minutes.|
|2.||Unlimited ice water on fields.|
|3.||Extend official time-outs for supervised water breaks.|
|4.||Helmets off on side-lines when not playing, and at all time outs.|
|5.||Electric fans in locker rooms at half-time to increase evaporation.|
|6.||Emergency medical personnel at games when heat and humidity are in the danger zone.|
|7.||Change practices and games to cooler times of day when heat and humidity are excessive.|
|8.||Move season back approximately two (2) weeks. Allow three (3) weeks preseason practice.|
|9.||Institute Psychrometer (Wet-Globe Thermometer) readings to determine heat humidity danger zones.|
The Indiana High School Athletic Association establishes rules and regulations for all sanctioned sports for participating in high schools.
|F.||Recommendations for Band|
|2.||Increase water before with frequent water breaks.|
|3.||Less bulky clothes.|
|4.||Not participating in extreme heat.|
|5.||When standing for extended lengths of time, unlock knees; and use muscle pump mechanism: alternately press and release toes, causing calf muscles to contract and relax (3 sets of 10). This technique helps prevent pooling of blood in the muscles.|
|G.||Recommendation for Classrooms|
|1.||Lightweight, light colored, loose clothing.|
|2.||Well ventilated areas.|
|3.||Frequent fluids (water) breaks.|
|4.||If outside, cautious physical activity.|
|5.||Contact local physicians or local health department for specific concerns.|
10 20 30 40 50 60 70 80 90 100
Relative Humidity (%)
0.7 1.3 2.0 2.7 3.3 4.0
200 400 600 800 1000 1200
Energy Expenditure (Kcal/hr)