HEAT ACCLIMATIZATION AND
EXERTIONAL HEAT ILLNESS
Bylaw 14.17 - Heat Acclimatization
and Exertional Heat Illness
14.17.1. It is the position of the Arizona Interscholastic Association (AIA) that prevention is the best way to avoid exertional heat stroke. Prevention includes educating athletes and coaches about:
1. Recognition and management of exertional heat illnesses;
2. The risks associated with exercising in hot, humid environmental conditions;
3. The need for gradual acclimatization over a fourteen (14) day period;
4. Guidelines for proper hydration;
5. Implementing practice/competition modifications according to local temperature and relative humidity readings.
14.17.2 - Definitions
Exertional heat illness includes the following conditions, ordered from the least to the most dangerous:
1. Exercise associated muscle cramps: an acute, painful, involuntary muscle contraction usually occurring during or after intense exercise, often in the heat, lasting approximately one to three (1-3) minutes.
2. Heat syncope: also known as orthostatic dizziness, it refers to a fainting episode that can occur in high environmental temperatures, usually during the initial days of heat exposure.
3. Exercise (heat) exhaustion: the inability to continue exercise due to cardiovascular insufficiency and energy depletion that may or may not be associated with physical collapse.
4. Exertional heat stroke: a severe condition characterized by core body temperature greater than forty degrees Celsius (> 40°C); one hundred four degrees Fahrenheit (104°F), central nervous system (CNS) dysfunction, and multiple organ system failure induced by strenuous exercise, often occurring in the hot environments.
Heat Acclimatization Protocol
Days One through Five:
● Days one through five (1-5) of the heat-acclimatization period consist of the first five (5) days of formal practice. During this time, athletes may not participate in more than one (1) practice per day.
● If a practice is interrupted by inclement weather or heat restrictions, the practice should recommence once conditions are deemed safe. Total practice time should not exceed three (3) hours in any one (1) day. In addition to practice, a one (1)-hour maximum walk-through is permitted during days one through five (1-5) of the heat-acclimatization period. However, a three (3)-hour recovery period should be inserted between the practice and walk-through (or vice versa). (Note: A walk-through is defined as no contact with other individuals, dummies, sleds or shields).
● During days one through three (1-3) of the heat-acclimatization period, in sports requiring helmets or shoulder pads, a helmet is the only protective equipment permitted. The use of shields and dummies during this time is permissible as a noncontact teaching tool.
● During days four through six (4-6), only helmets and shoulder pads may be worn.
● Football only: On days four through six (4-6), contact with blocking sleds and tackling dummies may be initiated.
Days Six through Fourteen:
● Beginning no earlier than day six (6) and continuing through day fourteen (14), double-practice days must be followed by a single-practice day.
● On single-practice days, one (1) walk-through is permitted, separated from the practice by at least three (3) hours of continuous rest. When a double-practice day is followed by a rest day, another double-practice day is permitted after the rest day.
● On a double-practice day, neither practice should exceed three (3) hours in duration, nor should student-athletes participate in more than five (5) total hours of practice. Warm-up, stretching, cool-down, walk- through, conditioning, and weightroom activities are included as part of the practice time. The two (2) practices should be separated by at least three (3) continuous hours in a cool environment.
● Beginning on day seven (7), all protective equipment may be worn and full contact may begin.
● Full-contact sports may begin one hundred percent (100%) live contact drills no earlier than day seven (7).
● Because the risk of exertional heat illnesses during the preseason heat-acclimatization period is high, we strongly recommend that an athletic trainer be on site before, during, and after all practices.
14.17.3 - Hydration Strategies:
● Sufficient, sanitary, and appropriate fluid should be readily accessible and consumed at regular intervals before, during, and after all sports participation and other physical activities to offset sweat loss and maintain adequate hydration while avoiding overdrinking.
● Generally, one hundred to two hundred fifty milliliters (100 to 250 ml; approximately three  to eight  oz.) every twenty (20) minutes for nine to twelve (9-12) year olds and up to one to one and one-half liters (1.0 to 1.5 L; approximately thirty-four to fifty ounces [34 -50] oz.) per hour for adolescent boys and girls is enough to sufficiently minimize sweating-induced body-water deficits during exercise and other physical activity as long as their pre-activity hydration status is good.
● Pre-activity to post-activity body-weight changes can provide more specific insight to a person's hydration status and rehydration needs. Athletes should be well-hydrated before commencing all activities (see guideline box format).
● The following guidelines are suggested:
Condition % Body Weight Change
Well hydrated +1 to -1
Minimal dehydration - 1 to - 3
Significant dehydration - 3 to - 5
Serious dehydration > - 5
% Body weight change = [(pre-exercise body weight -
postexercise body weight) / pre-exercise body weight] x 100
14.17.3 - Return to Play Following
Exertional Heat Stroke
The following is the protocol for return to play following heat stroke:
1. Refrain from exercise for at least seven (7) days following the acute event.
2. Follow up in about one (1) week for physical exam by a licensed physician (MD, DO).
3. When cleared for activity by a licensed physician, begin exercise in a cool environment and gradually increase the duration, intensity, and heat exposure for two (2) weeks to acclimatize and demonstrate heat tolerance under the direction of a licensed healthcare professional.
4. If return to activity is difficult, consider a laboratory exercise-heat tolerance test about one (1) month post-incident.
5. Athlete may be cleared for full competition if heat tolerance exists after two to four (2-4) weeks of training.
The AIA also recommends that any athlete suspected of having suffered exertional heat exhaustion be referred to a licensed physician for follow-up medical examination and clearance.
14.17 will be effective July 1, 2012 for 2102-2013. This proposed bylaw had input from the AIA Football Sports Advisory Committee via participation in the May 22, 2012 AIA Executive Board meeting and the May 24, 2012 AIA SMAC meeting. 14.17 will carry possible violations as they relate to football but will be recommendations, at this point, related to all other sports as reflected in each sport specific bylaw.
Questions regarding this bylaw can be directed to the AIA office via the athletic administrator and/or site administrator.
Reproduction of AIA Bylaw 14.17.