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Heat Information

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WIAA Fall Football Acclimatization Announced

The WIAA has been providing member schools and coaches with information about heat illness and the risk of EHI; and limits of two-a-day practices for years.  With a strong, evidence-based, effective policy for EHI, the WIAA will have an effective policy to protect the student-athlete. The acclimatization plan must be followed during summer contact if school resources are used. Read more.  NOTE:  After the 10th day of practice, teams may only practice a maximum of 2.5 hours without the required break (two-a-days are no longer beyond the 10th day). 

Fall Football Acclimatization (Course)

Heat a Priority

All athletic programs should have a Heat Acclimatization Program. Among the fundamentals of a Heat Acclimatization Program are 1) a slow progression in activity level – duration and intensity; 2) adjusting workouts as heat and humidity increase, including close monitoring and a prompt response to developing problems; and 3) proper hydration.  Read more.

NFHS Offers Free Heat Course

Member schools are encouraged to view the latest online, free course created by the NFHS entitled, "A Guide to Heat Acclimization and Heat Illness Detection" . The course is filled with relevant, up-to-date content on heat acclimatization and heat illness that coaches of all levels and experience will benefit from. Given the hot, dry summer and the fact that fall practices begin shortly, the timeliness of this course’s release could not be better. The course can be accessed through the NFHS Learning Center at www.nfhslearn.com.

This course should be a must see for coaches of all sports and this course can be taken on mobile devices, including ipads and tablets.

Heat Information

Model Policy for Heat and Humidity

Printable version

1.   Thirty minutes prior to the start of an activity, and again 60 minutes after the start of that activity, take temperature and humidity readings at the site of the activity. Using a digital sling psychrometer is recommended. Record the readings in writing and maintain the information in files of school administration. Each school is to designate whose duties these are: generally the athletic director, head coach or certified athletic trainer.

2.     Factor the temperature and humidity into the Heat Index Calculator and Chart to determine the Heat Index. If a digital sling psychrometer is being used, the calculation is automatic.

3.     If the Heat Index is below 95 degrees:

      All Sports

o   Provide ample amounts of water. This means that water should always be available and athletes should be able to take in as much water as they desire.

o   Optional water breaks every 30 minutes for 10 minutes in duration.

o   Ice-down towels for cooling.

o   Watch/monitor athletes carefully for necessary action.

If the Heat Index is 95 degrees to 99 degrees:

     All Sports

o   Provide ample amounts of water. This means that water should always be available and athletes should be able to take in as much water as they desire.

o   Optional water breaks every 30 minutes for 10 minutes in duration.

o   Ice-down towels for cooling.

o   Watch/monitor athletes carefully for necessary action.

     Contact sports and activities with additional equipment:

o   Helmets and other possible equipment removed while not involved in contact.

•     Reduce time of outside activity. Consider postponing practice to later in the day.

•     Recheck temperature and humidity every 30 minutes to monitor for increased Heat Index.

If the Heat Index is above 99 degrees to 104 degrees:

•     All Sports

o   Provide ample amounts of water. This means that water should always be available and athletes should be able to take in as much water as they desire.

o   Mandatory water breaks every 30 minutes for 10 minutes in duration.

o   Ice-down towels for cooling.

o   Watch/monitor athletes carefully for necessary action.

o   Alter uniform by removing items if possible.

o   Allow for changes to dry t-shirts and shorts.

o   Reduce time of outside activity as well as indoor activity if air conditioning is unavailable.

o   Postpone practice to later in the day.

•     Contact sports and activities with additional equipment

o   Helmets and other possible equipment removed if not involved in contact or necessary for safety. If necessary for safety, suspend activity.

     Recheck temperature and humidity every 30 minutes to monitor for increased Heat Index.

If the Heat Index is above 104 degrees:

    All sports

o   Stop all outside activity in practice and/or play, and stop all inside activity if air conditioning is unavailable.

Note: When the temperature is below 80 degrees there is no combination of heat and humidity that will result in need to curtail activity.

Sources:  Michigan High School Athletic Association

7 Fundamentals Heat Acclimatization/Heat Illness Prevention

• Exertional Heat Stroke (or EHS) is the leading cause of preventable death in high school athletics. 

 

• Exertional heat stroke can be prevented through acclimatization and taking  basic safety precautions. 

 

• Knowing the signs of exertional heat stroke and heat illness, and having an  emergency action plan in place can prevent serious illness and save lives. 

 

Follow these 7 fundamentals to keep every player safe! 

 

1. Physical exertion and training activities should begin slowly and continue progressively. An athlete cannot be “conditioned” in a period of only 2 to 3 weeks. 

 

2. Keep each athlete’s individual level of conditioning and medical status in mind and adjust activity accordingly. These factors directly affect exertional heat illness risk. 

 

3. With an increase in heat/humidity, especially if the heat and humidity level is a significant change from the previous few days: 

 

• Decrease intensity of activity 

 

• Increase frequency/duration of rest breaks 

 

• Reduce uniform/equipment 

 

Continue to closely monitor players in these changing conditions. 

 

4. Athletes must begin practices and training activities adequately hydrated. 

 

5. Recognize early signs of distress and developing exertional heat illness, and promptly stop activity for affected players and treat accordingly. Do not delay first aid! 

 

6. Recognize more serious signs of exertional heat-related distress. Immediately stop activity and seek medical attention by activating the emergency medical system. Begin on-site rapid cooling immediately. 

 

7. Develop an emergency action plan with clearly defined, written and practiced protocols. This should be in place before any emergency happens.

National Federation of State High School Associations ® 
 

 

Heat Related Illness

Fluid Replacement and Dehydration

  • Athletic performance declines with dehydration, beginning with a fluid loss equaling one to two percent of the athlete’s body weight.
  • It is important for all athletes to begin each exercise session well-hydrated.
  • Rehydration should consist of water, carbohydrates and electrolytes, as all are lost during exercise.
  • Athletes should never be punished through the restriction of fluids.

 

SIGNIFICANCE

In order for an athlete to perform at an optimal level, close attention must be paid to the body’s water and electrolyte levels. With many athletes focusing on specific aspects of their sport, along with the outcome of the event, many neglect the need for fluid replacement during activity. Many athletic events pose a challenge (e.g., very little rest) for the athlete to maintain optimal fluid levels, so it is important for athletes to have water or a sports drink close at hand in order to avoid poor performance or other detrimental physiological effects due to dehydration.

 

BACKGROUND

Minimal fluid loss can impair performance during exercise. At moderate exercise intensity, the human body generally produces 0.5 to 1.5 liters of sweat in one hour, but this may be higher in some individuals. The sweat rate increases as the intensity of exercise increases. During intense exercise in hot conditions, some individuals can lose up to three liters of sweat in one hour. A one percent drop in body weight due to fluid loss can lead to an increased core body temperature during exercise. When an athlete loses one to two percent of body weight due to fluid loss, aerobic exercise performance can decrease. When an athlete loses three percent or more of body weight, there is an increased risk for heat illness. Prevention of dehydration occurs before exercise begins, and should include a hydration protocol agreed upon by coaches, athletic trainers and all others involved in the well-being and performance of a team or athlete. 

 

Pre-exercise Hydration 
It is important for all athletes to begin each exercise session well-hydrated. Ideally, athletes should monitor their weight before and after exercise sessions in order to replace any fluids lost. It is recommended that an athlete consume 16 ounces (two cups) of water two hours before exercise begins. Another eight to 16 ounces (one to two cups) should be consumed 15 minutes prior to exercise.

 

Maintaining Hydration During Exercise 
Fluid replacement during exercise should equal fluid lost through sweat and urine, at a rate no higher than 48 ounces per hour. As previously stated, fluid loss of one to two percent of body weight can decrease aerobic performance, so the goal of the athlete should be to minimize dehydration to less than two percent loss of body weight, with less than one percent loss of body weight being optimal.

Unfortunately, relying on the body’s thirst mechanism cannot prevent dehydration, so thirst should not be relied upon to determine fluid intake. By the time a person becomes thirsty, he or she is already dehydrated. An athlete should drink early and often, and be allowed unrestricted fluid replacement. Athletes should never be punished through the restriction of fluids. Unrestricted access to water or sports drinks should lead to the consumption of four to eight ounces (one-half to one cup) of fluid every 15 minutes. It is important to remember that some athletes may have a higher sweat rate than others and require more fluids to remain well hydrated. These athletes can safely tolerate up to 48 ounces per hour.

 

Some sports present rehydration challenges, such as soccer or certain running events. A cross country race can last up to 30 to 40 minutes for some runners and water stations should be set-up with consideration given to the course and climate. In all settings, allowing athletes to drink as much fluid as they feel necessary is important.

 

Post-exercise Rehydration 
Fluid replacement after exercise should aim at achieving the athlete’s pre-practice or pre-event weight. Ideally, this should occur before the next practice session or competition. However, this may not be possible if there is minimal time between competition. Consumption of 16-20 ounces (2-2½ cups) of fluid for every pound lost during exercise will help achieve normal fluid state. Rehydration should consist of water, carbohydrates and electrolytes, as all are lost during exercise.

At the beginning of the fall sports season, athletes often participate in twice daily practices, and rehydration becomes even more important during this time. Athletes may be weighed prior to and after each practice session. If the athlete has not returned back to previous weight before the start of the second session, the athlete should be held out of participation in order to avoid dehydration-related illness.

 

Hyponatremia

Hyponatremia is extremely rare in high school athletics, but deserves mention. This is a potentially deadly disorder that results from the over-consumption of fluids (water and sports drinks). It is most commonly seen during endurance 
events, such as marathons, when adult participants consume large amounts of water over several hours in the absence of significant sweating. The opposite of dehydration, hyponatremia is a condition where the sodium content of the 
blood is diluted to dangerous levels. Affected individuals may exhibit disorientation, altered mental status, headache, lethargy and seizures. The diagnosis can only be made by testing blood sodium levels. Suspected hyponatremia is a medical emergency and EMS (Emergency Medical Services) must be activated. It is treated by administering intravenous fluids containing sodium.

 

RECOGNITION

Dehydration is common in all sports and can occur very rapidly, especially in a warm or hot environment or if the athlete starts activity less than fully hydrated. All coaches and athletes must be aware of the signs and symptoms of dehydration (Table 17). The volume and color of urine is an excellent way of determining if an athlete is well hydrated. A normal amount of nearly clear or light-colored urine indicates that an athlete is well-hydrated; small amounts of dark urine point to the need to increase fluid intake. A Urine Color Chart can be accessed at: 
http://at.uwa.edu/admin/UM/urinecolorchart.doc.

 

Table 17.  Signs and symptoms of dehydration. 
 Thirst 
 Irritability 
 Headache 
 Weakness 
 Dizziness 
 Muscle cramps 
 Chills 
 Nausea and vomiting 
 Heat sensations in the head 
or neck 
 Decreased performance

PREVENTION AND MANAGEMENT

Sports drinks and energy drinks are commonly seen in advertisements and differ in their ingredients. A sports drink is designed to provide re-hydration during or after an athletic activity. Most sports drinks contain six to eight percent carbohydrate solution and are a good source of electrolytes. Carbohydrate and electrolyte concentrations are formulated to allow the body’s gastrointestinal tract to absorb the fluid as efficiently as possible. 

 

Sports drinks can provide water, energy and appropriate electrolytes during competition. A carbohydrate concentration of six to eight percent can provide energy, while the higher concentration of carbohydrates found in juices and energy drinks will produce slow emptying of the stomach and may leave the athlete feeling bloated. The lower concentration of sodium found in sports drinks may also help avoid abdominal cramping. While sports drinks provide some benefits during exercise (Table 18), the main focus of an athlete’s hydration protocol should be on water. With an adequate diet and water intake, athletes will be properly prepared for practice and competition.

 

Table 18.  Indications for the use of sports drinks. 
Traditional sports drinks with appropriate carbohydrates and sodium 
may provide additional benefit in the following general situations: 
 Prolonged continuous activity of greater than 45 minutes 
 Extremely intense activity with risk of heat illness 
 Hot and humid conditions 
 Individuals who are poorly hydrated prior to participation 
 Individuals with an increased sweat rate 
 Individuals with poor caloric intake prior to participation 
 Individuals with poor acclimatization to heat and humidity  

Energy drinks were originally marketed towards athletes as a means of rehydration and electrolyte replacement during activity. Companies that manufactured the energy drinks claimed they improved performance on the field – both in practice and games. In recent years, energy drink companies have targeted the general  population and the market has been saturated with different energy drinks containing many different ingredients.

 

In 2006, nearly 500 new energy drink brands were introduced, often touting false claims of performance enhancement and improved recovery. Energy drinks may contain carbohydrates, caffeine, taurine and other substances that manufacturers claim enhance performance. Energy drinks ARE NOTrecommended for pre-hydration or rehydration during or after activity. Some ingredients, such as caffeine, may act as a diuretic, and can lead to even greater fluid loss. Please see the NFHS Position Statement on The Use of Energy Drinks by Young Athletes.

 

References 
Casa DJ, et al. National Athletic Trainers’ Association Position Statement: Fluid replacement for athletes. Journal of Athletic Training 2000; 35:212-224.

 

McKeag DB, Moeller JL. ACSM’s Primary Care Sports Medicine. 2nd Ed, Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins, 2007.

 

Position Statement and Recommendations for Hydration to Minimize the Risk for Dehydration and Heat Illness, National Federation of State High School Associations; Sport Medicine Advisory Committee. April 2008.

 

Position Statement and Recommendations on the Use of Energy Drinks by Young Athletes. National Federation of State High School Associations; Sport Medicine Advisory Committee.October 2008.


Heat Recommendations

POSITION STATEMENT AND RECOMMENDATIONS  FOR HYDRATION TO MINIMIZE THE RISK FOR  DEHYDRATION AND HEAT ILLNESS 
 
National Federation of State High School Associations (NFHS) 
Sports Medicine Advisory Committee (SMAC) 
 
 
DEHYDRATION, ITS EFFECTS ON PERFORMANCE, AND ITS RELATIONSHIP TO HEAT ILLNESS: 
 
 

Appropriate hydration before, during, and after exercise is an important ingredient to healthy and successful sports participation. 

Rapid weight loss represents a loss of body water.  A loss of just 1-2% of body weight (1.5 to 3 pounds for a 150 pound athlete) can negatively impact performance.  A loss of 3% or more of body weight can increase the risk for exertional heat related illness.  

Athletes should be weighed before and after warm weather practice sessions and contests to assess fluid losses.  

Athletes with high body fat percentages can become dehydrated faster than athletes with lower body fat percentages while working out under the same environmental conditions.

All athletes have different sweating rates and some lose much more salt through their sweat than others. 

Poor acclimatization/fitness levels can greatly contribute to an athlete’s dehydration problems.

Medications and fevers can each greatly contribute to an athlete’s dehydration problems and risk for heat illness.

Environmental temperatures and humidity both contribute to dehydration and heat illness.

Clothing, such as dark, bulky, or rubber protective equipment can drastically increase the chance of dehydration and heat illness.

Wet bulb temperature measurements should be taken 10-15 minutes before practices or contests. The results should be used with a heat index to determine if practices or contests should be started, modified, or stopped.

Even dry climates can have high humidity if sprinkler systems are scheduled to run before early morning practices start. This collection of water does not evaporate until environmental temperatures increase and dew points lower. 

A heat index chart should be followed to determine if practices/contests should be held. The NOAA National Weather Service’s heat index chart can be found at:http://www.weather.gov/om/heat/index.shtml#heatindex

 

The heat index for your location can be determined by entering your postal zip code into a weather web site.  However, best practice is to take the temperature and humidity one half hour before activity at the site with additional measurements throughout activity.

A relative humidity of 35 percent and a temperature of 95 degrees Fahrenheit are likely to cause heat illness, with heat stroke likely.

 

A relative humidity of 70 percent and a temperature of 95 degrees Fahrenheit are very likely to cause heat illness, with heat stroke very likely.

 

 
WHAT TO DRINK DURING EXERCISES: 
 

For most exercising athletes, the ideal fluid for pre-hydration and re-hydration is water.  Water is quickly absorbed, well tolerated, an excellent thirst quencher, and cost effective.   
 
 
The use of a sports drink with appropriate carbohydrates (CHO) and sodium as described below may prove beneficial in some general situations and for some individuals.   
 
 
Traditional sports drinks with appropriate CHO and sodium may provide additional benefit in the following general situations: 
  Prolonged continuous activity of greater than 45 minutes 
  Extremely intense activity with risk of heat injury 
  Extremely hot and humid conditions 
 
 
Traditional sports drinks with appropriate CHO and sodium may provide additional benefit for the following individual conditions: 
  Poor hydration prior to participation 
  Increased sweat rate 
  Poor caloric intake prior to participation 
  Poor acclimatization to heat and humidity 
 
 
A 6-8% addition of CHO to water is the maximum that should be utilized.  Any greater concentration will produce slow emptying from the stomach and a bloated feeling to the athlete. 
 
 
The other ingredient that may be helpful is a low concentration ( 0.3 - 0.7 g/L) of sodium which may help with cramping.   
 
 
All fluids should be served cold to optimize gastric emptying. 
 
 
  
WHAT NOT TO DRINK DURING EXERCISE: 
 
 
Fruit juices with greater than 8 percent carbohydrate content and soda can both result in a bloated feeling and abdominal cramping. 
 
 
Beverages containing caffeine, alcohol, and carbonation are not to be used because of the high risk of dehydration associated with excess urine production, or decreased voluntary fluid intake. 
 
 

These stimulants may increase the risk of heart or heat illness problems  when exercising. 

 
Many of these drinks are being produced by traditional water, soft drink,  and sports drink   companies and may provide confusion to the sports community. As is true with other forms of    supplements these "power drinks or fluid supplements" are not regulated by the FDA.  Thus,    the purity and accuracy of contents on the label are not guaranteed.   
  
Many of these beverages, which claim to provide additional power, energy, etc., have   additional ingredients that are not necessary, some that are potentially harmful, and some  that actually include substances banned by such governing bodies as the NCAA and the  USOC.  

 
HYDRATION TIPS AND FLUID GUIDELINES: 
 
 
In general, athletes do not voluntarily drink sufficient water to prevent dehydration during physical activity. 
 
 
Drink early, by the time you’re thirsty, you’re already dehydrated. 
 
 
Drink before, during, and after practices and games. Specifically, the American College of Sports Medicine recommends the following:

Drink 16 ounces of fluid 2 hours before exercise.

Drink another 8 to 16 ounces 15 minutes before exercise. During exercise, drink 4 to 16 ounces of fluid every 15 to 20 minutes.

During exercise, drink 4 to 16 ounces of fluid every 15 to 20 minutes.

After exercise, drink 24 ounces of fluid for every pound lost during  exercise to achieve normal    fluid statue within 6 hours.

 

The volume and color of your urine is an excellent way of determining if you’re well hydrated. Largeamounts of clear urine mean your hydrated, small amounts of dark urine mean that you need to drink more! A Urine Color Chart can be accessed at: http://at.uwa.edu/admin/UM/urinecolorchart.doc 

 

The NFHS SMAC strongly recommends that coaches, certified athletic trainers, physicians, and other school personnel working with athletes not provide or encourage use of any beverages for hydration of these youngsters other than water and appropriate sports drinks that meet the above criteria.  They should also make information on the potential harm and lack of benefit associated with many of these other beverages available to parents and athletes.    
 
 
 
References: 
 
Casa DJ, Armstrong LE, Hillman SK, Montain SJ, Reiff RV, Rich BSE, Roberts WO, Stone JA.

National Athletic Trainers’ Association Position Statement:  Fluid Replacement for Athletes.  Journal of Athletic Training. 35(2):212-224, 2000.   
 
McKeag DB, Moeller JL. ACSM’s Primary Care Sports Medicine. 2nd Ed, Philadelphia: Wolters 
Kluwer/Lippincott Williams & Wilkins, 2007. 
 
 
Revised and Approved April 2008 


Proper Conditioning

Heatstroke and heat exhaustion is preventable if the proper precautions are taken.  Have water available at all times and to allow the athlete to drink water whenever he/she needs it.  Never restrict the amount of water an athlete drinks, and be sure the athletes are drinking the water. 

In addition, allow time for young athletes to adapt to the weather and provide rest more often.  Progressive acclimatization is critical.  Provide for gradual increases in frequency, duration and intensity of physical activity. The key is recovery.  Also, remove equipment during rest periods and change to dry shirts.