Environmental Considerations
Heat can be gained or lost through:
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Metabolic Heat Production
o
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Conductive Heat Exchange
o
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Example: radiant heat from sunshine (sun vs. shade)
Evaporative Heat Loss
o
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Example: Physical contact with other object (football player vs turf)
Radiant Heat Exchange
o
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Example: Normal metabolic function (Digestion)
Example: Sweating
Convective Heat Exchange
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Example: Sweating
Hyperthemia
Statistic: During 1999-2003 a total of 3,442 deaths result from exposure to extreme heat were reported
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Prolonged exposure to extreme heat can result in heat illness
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The physiological processes in the body with a continue to function only as long s body temperature is maintained
within a normal range
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The maintenance of normal temperature in a hot environment depends on the body’s ability to dissipate heat
Variations in Sweat Rates:
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Athlete’s height & weight (heavier athletes sweat more)
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Degree of acclimatization (well acclimated athletes sweat earlier and more)
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Fitness level (fit athletes sweat more)
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Hydration status
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Environmental conditions
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Clothing
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Intensity and duration of activity
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Heredity
Color Code
No Flag
Guidelines
Not Acclimated: Extreme exertion may precipitate heat illness
<78.0*F
Green
78*F—82*F
Yellow
82.1*F-86*F
Red
86.1*F-89.9*F
Black
Fully Acclimated: Normal Activity
Use discretion in planning intense exercise
Normal Activity: Pay special attention to at-risk individuals in both cases
Limited intense exercise to 1 hour, total outdoor exercise to 2.5 hours
Use Discretion in planning intense physical activity. Watch high risk individ.
Stop Outdoor practice sessions & outdoor physical conditioning
Limit intense exercise to 1 hour, limit outdoor exercise to 4 hrs (High alert for S&S)
Both: Cancel all outdoor exercise requiring physical exertion
≥90*F
Exertional Heat Illness
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Exercising in a hot, humid environment can cause various forms of heat illness, including heat rash, heat syncope,
heat cramps, heat exhaustion, exertional heat stroke, and exertional hyponatremia
Heat Rash
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AKA: prickly heat
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Condition associated with a red, raised rash accompanied by sensations of prickling and tingling during sweating
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Usually occurs when the skin is continuously wet with unevaporated sweat
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Typically occurs with areas that are covered with clothing
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Continually toweling the body can help prevent the rash from developing
Heat Syncope
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AKA: Heat Collapse
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Associated with rapid physical fatigue during overexposure to heat
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Typically caused by standing in heat for long periods or by not being accustomed to exercising in heat
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Quickly relieved by laying the athlete down in a cool environment and replacing fluids
Heat Cramps
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Most often occur in the calf and abdomen (although any muscle can be involved)
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Occurs due to excessive loss of water and several electrolytes or ions
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Profuse sweating involves losses of large amounts of water and small quantities of sodium, potassium, magnesium,
and calcium
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The person most likely to get heat cramps is one who is in fairly god condition but who is not acclimated to the
heat
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Prevention: adequate replacement of sodium, chloride, potassium, magnesium, calcium, and most important fluids
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Immediate treatment: ingestion of large quantities of fluids, preferably a sport drink, and mild prolonged
stretching with ice massage
Exertional Heat Exhaustion
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More moderate form of heat illness that occurs from environmental heat stress and strenuous physical exercise
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Athlete becomes dehydrated to the point that he is unable to sustain adequate cardiac output and cannot
continue intense exercise
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Rectal temperature is less than 104*F and no evidence of CNS dysfunction
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S&S: dehydration, profuse sweating, stomach cramps, nausea, vomiting or diarrhea, headache, dizziness
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Treatment:
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Remove immediately and take to shade / air conditioning
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Excess clothing or equipment should be removed and athlete should lie down with legs elevated
o
Rehydrate immediately
o
Monitor heat rate, blood pressure, and core temperature
Exertional Heatstroke
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Serious life-threatening emergency (most severe form of heat illness)
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Caused by strenuous physical exercise and increased environmental heat stress
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Potential tissue damage and CNS abnormalities resulting from elevated body temperature
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Occurs suddenly and without warning
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Sudden collapse with CNS dysfunction, altered consciousness, seizures, confusion, and emotional instability,
irrational behavior
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Rectal temperature is 104*F or higher
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Signs & Symptoms
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Body loses the ability to dissipate heat through sweating
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The possibility of death can be significantly reduced if the victims body temperature is lowered to normal ASAP
Exertional Hyponatremia
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Condition involving a fluid/electrolyte disorder that results in an abnormally low concentration of sodium in the
blood
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Most often caused by ingesting so much fluid before, during, and after exercise in an abnormally low
concentration of sodium in the blood
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Can be avoided completely by making certain that fluid intake during exercise does not exceed fluid loss and that
sodium intake is adequate
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Signs & Symptoms:
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Progressive worsening headache
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Vomiting
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Swelling of hands & feet
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Lethargy
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Agitation
NATA Recommendation for Preventing Heat Illness
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Ensure that appropriate medical care is available
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Conduct a thorough physical-supervised PPE
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Acclimatize athletes over 10-14 days
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Encourage athletes to sleep six to eight hours per night
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Weight high-risk athletes before and after practice to make certain they are not dehydrated
Dehydration:
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An individual is said to have mild dehydration when fluids lost are less than 2% of normal body weight
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Even mild dehydration can impair cardiovascular and thermoregulatory response and can reduce the capacity for
exercise and have a negative effect on performance
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Signs & Symptoms:
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Thirst
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Dry Mouth
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Headache
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Dizziness
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Irritability
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Excessive Fatigue
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Cramps
Acclimatization:
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Involves becoming accustomed to heat and exercising in hot temperatures
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Good pre-season conditioning program started before season is highly recommended
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Progressive exposure should occur over a 7-10 day period (NATA: 10-14 Days)
Common Cold Injuries
Frost Nip:
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Involves: ears, nose, cheeks, chin, fingers and toes
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Occurs when there is high wind, severe cold, or both
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Skin initially appears very firm with cold, painless areas that may peel or blister in 24-72 hours
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Treatment:
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Firm, sustained pressure of hand (ribbing) by blowing hot breath on the spot
Frost Bite:
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Chilblains
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Result from prolonged and constant exposure to cold for many hours
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Signs & Symptoms:

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Skin redness, swelling, tingling, and pain in the toes and fingers
Superficial Frostbite
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Skin and subcutaneous tissue
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Skin appears pale, hard, cold, and waxy
Deep Frostbite
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Tissue is frozen
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Medical emergency
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Tissue is cold, hard, pale or white or numb
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Rapid rewarming is needed; tissue will become blotchy red, swollen, and extremely painful
Hypothermia
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Low temperatures accentuated by wind and dampness can pose major problems for athletes
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65% of the heat produced by the body is lost through radiation (typically involving the head and neck)