Heat Illness and Prevention

Heat illness is a preventable sports-related illness. It is an accumulation of body heat that results when the body's ability to cool itself is overwhelmed. Although most of the heat problems have been associated with football, heat illnesses can strike any athlete in any sport, during any time of the year. There are no excuses for heatstroke deaths.

Dehydration is a risk factor for heat illness. Exercise in hot, humid conditions can cause significant dehydration in as little as 30 minutes. Athletes need to drink regularly because thirst is not a reliable indicator of either dehydration or fluid needs. Thirst mechanisms don't kick in until an athlete has lost 2% of body weight as sweat—at this level sports, performance is already impaired.  Coaches, parents and athletes should be reminded to stay properly hydrated. This means drinking when you may not feel thirsty and avoiding carbonated or sugar-laden beverages.

The symptoms of heat illness range from mild to life-threatening. The heat is no time to tough it out. Recognizing mild symptoms early helps prevent more serious conditions. The following chart shows the various types of heat illnesses and how to recognize them.

Prevention Guidelines

• Allow for acclimatization (adaptation) to hot, humid conditions. Gradually increase workout intensity and duration over a 10- to 14-day period. This helps train your body to drink more, increase blood volume and sweat better. This prepares your body for more intense, longer-duration exercise in warm conditions, and helps prevent injury and heat illness.
• Intersperse periods of rest during activity and assure adequate rest between exercise bouts. Rest breaks are an important defense against heat illness, and proper sleeping habits decrease your risk as well.
• Coaches need to stay on top of athletes and make sure they are actually using water breaks and re-hydrating during them. Just by giving athletes water breaks does not mean they are drinking enough.
• Drink early.  Begin outdoor activities only after you’re properly hydrated. By the time you’re thirsty, you’re already dehydrated.
• Drink up when it's hot and when it's not! There should be unlimited access to fluids throughout practices and contests. Drink water or sports drinks throughout physical activity in the heat.
• A darker urine color is a quick indicator of dehydration. Your urine should look more like lemonade than apple juice.
• Do strenuous exercise in the early morning or late evening, not during the heat of the day. If this cannot be avoided, modify workout intensity and increase the number and length of rest breaks.
• Do not participate in intense exercise if you show signs of an existing illness (i.e. fever, diarrhea, extreme fatigue, etc.). These can decrease your body’s tolerance for heat and increase your risk of a heat illness. Back off on exercise intensity or duration if not feeling well (i.e. walk instead of run, cut the session short, etc.)
• Observe your athletes for signs of trouble.
• Know the risk factors that can increase the risk of heat illness:
  • Use of heavy equipment or clothing
  • Eating disorders
  • Obesity
  • Poor conditioning
  • Certain medications (e.g., diuretics)
  • Chronic or long-term diseases (e.g., diabetes)
  • Alcohol consumption or other substance abuse (heroin, cocaine, Ecstasy)
  • Recent move to a hot/humid climate

Heat Illnesses: Signs, Symptoms, & What to Do
Heat Illness	Definition/Description	Signs/Symptoms	What to Do
Muscle (Heat) Cramps	Occurs during or after intense exercise. Athlete will experience acute, painful, involuntary muscle contractions typically in the arms, legs, or abdomen.	Dehydration Thirst Fatigue Sweating Muscle cramps	Stop all activity and sit quietly in a cool place.       Drink clear juice or a sports drink.       Do not engage in exercise/strenuous activity for a few hours after cramps subside, as this may lead to heat exhaustion or heat stroke.       Seek medical attention if heat cramps do not subside in 1 hour.
Heat Syncope	Occurs as result of exposure to high temperatures.  Typically occurs during the first 5 days of acclimation to physical activity in the heat.  May also occur after a long period of standing after physical activity.	Dehydration Fatigue Fainting Lightheadedness Tunnel Vision Pale or sweaty skin Decreased pulse rate	Lie down in a cool place.       Drink clear juice or a sports drink.
Heat (Exercise) Exhaustion	The inability to continue exercising that is associated with heavy sweating, dehydration, energy depletion, and sodium loss. *Frequently occurs in hot, humid conditions	Normal or elevated body-core temp (97-104°F) Dehydration Dizziness/Lightheadedness Headache Nausea/Diarrhea Weakness Persistent muscle cramps Profuse sweating Chills Cool, clammy skin	You may attempt to cool the athlete using: cool, non-alcoholic beverages (as directed by physician), rest, cool shower/bath/sponge bath, moving to an air conditioned environment, and wearing lightweight clothing.       Seek medical attention immediately if symptoms are severe, the athlete has existing heart problems or high blood pressure.
HeatStroke	Life-threatening unless promptly recognized and treated.   Occurs as a result of prolonged heat exposure while engaging in physical activity.   Symptoms are a result of the body shutting down when it is no longer able to regulate temperature naturally.	Same Symptoms as Heat Exhaustion and: High body-core temp (>104°F) Change in Mood (e.g., apathy, irrational) Hot and wet or dry skin Increased heart rate Confusion	If any symptoms are evident-CALL 9-1-1 or seek immediate medical assistance.       Move the athlete to a shady area.       Cool the athlete rapidly using whatever methods you can: immerse the victim in a tub of cool water; place the person in a cool shower, spray the victim with cool water from the hose, sponge the person with cool water; fan the athlete.       Monitor body temperature and continue to cool the athlete until temp drops to 101-102°F.       Continue until medical professionals arrive and take over, if medical attention is delayed; call the emergency room for further instructions.
References
Brinkley, H.M., Beckett, J., Casa, D.J., Kleiner, D.M., & Plummer, P.E., (2002). National Athletic Trainers' Association position statement: Exertional Heat Illnesses. Journal of Athletic Training, 37 (3), 329-343.
Center for Disease Control (2003). Hot Weather Health Emergencies. Retrieved from http://www.cdc.gov/nceh/hsb/extremeheat/heatillness.htm. (June 14, 2004).

 

Hydration Guidelines

• Athletes should drink at least 16 oz. (2 cups) of fluid 2 hours before practice or competition.
• Athletes should drink 7 – 10 oz. of fluid 10-20 minutes before practice or competition.
• Athletes should drink 5 – 10 oz. of fluid every 15 minutes or so during exercise activities.
• After practice or competition an athlete should drink 24 oz of fluid for each pound of weight lose.
•  Athletes should avoid beverages that contain caffeine or high amounts of sugar as these may increase one’s dehydration.