Heat Index and Severe Weather Participation Policy
The following are guidelines and information for trainers, coaches, and supervisors to understand and implement to help prevent heat related and/or severe weather related illnesses, injuries, and emergencies. These guidelines should be strictly followed.
Heat Index Policy:
Heat illness and injury can range from a simple muscle cramp to life threatening heat stroke. Catastrophic heat injuries are preventable. The most important components in preventing heat injury are the prevention of dehydration and limiting activity when temperature and humidity make it near impossible for the body to cool through its normal evaporation of sweat. The body produces heat at rest, and this heat production increases 10-20 times with exercise. Evaporation is the major cooling method for the body, dissipating the heat from the core of the body, keeping the internal organs cool. Exercising in a dehydrated state reduces the ability t sweat, therefore compromising the ability to cool. Dehydration also causes a reduction in blood volume, compromising cardiac output.
The air temperature and humidity have a direct effect on the efficiency of this cooling process.
Based on the effects of dehydration and exercising in the heat and humidity, the following guidelines have been established to provide a sound plan to prevent heat injuries. These guidelines should apply to sports team activities, but shall also include activities such as marching band, cheerleading, dance teams, and physical education courses taught during the school day. The acclimatization process takes a minimum of 8 to 12 days, so coaches and supervisors should be diligent in monitoring environmental conditions and student preparedness, particularly in cases where there has been NO pre-season acclimatization regimen. Each exposure should involve a gradual increase in the amount, intensity, and duration of exercise in such cases.
Relative Humidity %
Air Temp | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% | 100% |
105 | 100 | 105 | 113 | 123 | 135 | 149 | ||||
104 | 98 | 104 | 110 | 120 | 132 | 143 | ||||
102 | 97 | 101 | 108 | 117 | 125 | 139 | ||||
100 | 95 | 99 | 105 | 110 | 120 | 132 | 144 | |||
98 | 93 | 97 | 101 | 106 | 110 | 125 | 132 | |||
96 | 91 | 95 | 98 | 104 | 108 | 120 | 128 | |||
94 | 89 | 93 | 95 | 100 | 105 | 111 | 122 | 128 | ||
92 | 87 | 90 | 92 | 96 | 100 | 106 | 115 | 122 | ||
90 | 85 | 88 | 90 | 92 | 93 | 100 | 106 | 114 | 122 | 130 |
88 | 82 | 86 | 87 | 89 | 93 | 95 | 100 | 106 | 115 | 125 |
86 | 80 | 84 | 85 | 87 | 90 | 92 | 96 | 100 | 109 | 111 |
84 | 78 | 81 | 83 | 85 | 86 | 89 | 91 | 95 | 99 | 105 |
82 | 77 | 79 | 80 | 81 | 84 | 86 | 89 | 91 | 95 | 96 |
80 | 75 | 77 | 78 | 79 | 81 | 83 | 85 | 86 | 89 | 91 |
78 | 72 | 75 | 77 | 78 | 79 | 80 | 81 | 83 | 85 | 86 |
76 | 70 | 72 | 75 | 76 | 77 | 77 | 77 | 78 | 79 | 80 |
Humiture Chart interpretation:
Less than 89 Heat Index:
* Careful monitoring of all participants for signs of heat problems.
* Adequate water supply at practice and competitions with 5 minute water breaks scheduled per every 30 minutes of activity.
90 – 99 Heat Index:
* Careful monitoring of all participants for signs of heat problems.
* Adequate water supply at practice and competitions with 5 minute water breaks scheduled per every 20 minutes of activity.
100 – 105 Heat Index:
* Extremely careful monitoring of all participants for signs of heat problems.
* Recommend equipment be removed as often as possible (during breaks, between drills)
* Adequate water supply readily available at all times during practice, with at least a 5 minute break, in a shaded or covered area, per every 15 – 20 minutes of physical activity.
106 – 110 Heat Index:
* Overly cautious monitoring of all participants for signs of heat problems.
* Any complaint of nausea, dizziness, overheating, etc. should be handled by immediate removal from activity and environmental conditions.
* Protective equipment, i.e., helmets, shoulder pads, catchers gear, etc. removed.
* Outside activity time should be reduced to 60 minutes or less, with 5 minute water breaks, in a shaded or covered area, scheduled at least every 15 minutes of activity.
* Adequate water supply readily available at all times during activity.
* Participants should be allowed to change into dry clothing or uniforms if necessary.
111+ Heat Index:
Stop all outside activity.
Signs and Symptoms of Heat Problems:
- Muscle spasms / cramps
- Heavy or profuse sweating
- Skin is flushed or cool and pale
- Headache
- Dizziness
- Rapid pulse, nausea, weakness
- Disoriented, confused
- Elevated body core temperature
- Cessation of sweating mechanism
- Red, dry skin
- Shallow breathing and rapid pulse
- Loss of consciousness
Heat Related Illness / Injury Facts:
- Adolescents take longer to acclimatize to the heat than adults
- Weight loss of water greater than 3% of body weight significantly increases the risk
- 1.5 times the amount of water lost must be consumed to replace lost weight.
- Unrelated illness causing vomiting and/or diarrhea will increase the risk.
- Certain medications, including diuretics, antihistamines, beta blockers and anti-cholinergics are at higher risk
- Light colored, breathable clothing will assist the body in cooling
- Participants who are overweight, poorly conditioned, recovering from illness or injury, lacking in sleep or taking medications are at added risk for problems.
Guidelines for Proper Hydration and Nutrition:
- DID YOU KNOW? You need 8 oz. of water for every waking hour.
- The thirst mechanism is 2-3 days behind – by the time you are thirsty, you are possibly already nearly dehydrated
- Dehydration of only 1% of body weight negatively affects your performance.
- An easy way to measure your hydration status is the color of urine: Drink until it is clear.
- BEFORE PRACTICE: Drink 20 oz. of water 2-3 hours beforehand
- BEFORE PRACTICE: Drink another 10 oz. right before practice
- BEFORE PRACTICE: Record your pre-practice weight.
- DURING PRACTICE: Drink 10 oz. of water every 20 minutes
- DURING PRACTICE: Drink beyond your thirst!
- AFTER PRACTICE: The best time to replace fluid with water or a sports drink is immediately after practice – rehydration should be complete within 2 hours
- AFTER PRACTICE: Compare pre-practice and post-practice weight…losing more than 2% of body weight requires that you return to normal hydration status before another practice session.
- AFTER PRACTICE: It takes at least 20oz. of water to replace every 1 lb. lost.
- BETWEEN PRACTICES: Eat foods with high water content and carbohydrates
- BETWEEN PRACTICES: Avoid foods with high fat content. Salt intake can be slightly increased by way of salting foods, but salt tablets should not be consumed.
- BETWEEN PRACTICES: Avoid drinks with caffeine, alcohol, carbonation, or high sugar. (Some sports drinks are high in sugar, so do not restrict your intake to just these)
