Environmental Considerations
for Athletic Trainers
Heat Illness, Hydration
& Hypothermia
Today’s topics...
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Clinical examination introduction
Categories of Heat Illness
Treatment of Heat Illness
Reducing the Risk of Heat Illness
Maintaining Hydration
Cold injuries
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Clinical Examination of
Environmental Conditions
• Requires knowledge of
– Symptoms
– Environmental conditions
– Predisposing factors
Heat Illness
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Heat rash
Heat syncope
Heat cramps
Heat exhaustion
Heat stroke
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Environmental Pathologies and
Related Special Tests
• Illnesses from heat or cold exposure are preventable.
• It is difficult to differentiate between types and severity.
Heat Illnesses
• Hyperthermia
– Effects of participating in hot, humid environment
Predisposing conditions
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Large body mass
Age
Conditioning level
Poor hydration
History of heat illness
Medications
Chronic disease
Heat Cramps
• Painful involuntary muscle spasms
• Predisposing factors
– Unconditioned
– Un-acclimated
• Cause unknown
– Dehydration
– Loss of electrolytes
– Neuromuscular fatigue
• Minimize risk for those prone to cramping
• Typical locations
• Treatment
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Heat Syncope
• Fainting spell caused by hot, humid
environments
• Different than fainting caused by heat
exhaustion
– No elevated core temperature
– Hydrated
Heat Exhaustion
• Sudden, extreme fatigue as the body attempts to
supply blood to the brain, muscles, and skin
• Hypothalmus continues to function properly
• Two types of heat exhaustion
– Water depletion heat exhaustion
– Electrolyte depletion heat exhaustion
Heat Exhaustion
• Variety of signs/symptoms
1. Fatigue
2. Cool, clammy skin
3. Skin pale or grayish
4. General weakness or uncoordinated gait
5. Nausea, vomiting
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Heat Exhaustion
• Symptoms, continued
6. Small urine output
7. Headache
8. Rapid & shallow respirations
9. Rapid, weak pulse
10. Elevated core temperature (103°)
• Treatment
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Heat Stroke
• Failure and shutdown of the body’s
thermoregulatory system
• Core temperature > 104°F
• Death can occur within 20 minutes
• Classic or exertional heat stroke
Heat Stroke
Exertional
• Profuse sweating occurs and
fluids are not replaced
– Can occur without
significant dehydration
• Athletes will be sweating
• How to tell on the field if its
Heat exhaustion or heat
stroke?
– Neurologic changes
– Violent or unconscious
– Hot skin
– Decerebrate position
Classic
• Infants or the elderly
• Exposed to hot environment
and cannot cool or rehydrate
themselves
• Absence of sweat
Heat Stroke
Heat Stroke
heat stroke
• Signs/symptoms of
1. Hot, dry, red skin
2. Dizziness
3. Light-headedness or headache
4. Disoriented or incoherent
5. Collapse or coma
6. Marked temperature increase
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Heat Stroke
Heat Stroke
• Symptoms represent failure of central
nervous system
• Temperatures above 104° risk brain damage
• Seek medical attention immediately
• Cool w/whatever means possible
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Emergency Cooling of an Athlete
Suffering from Heat Illness
Heat Illness is Preventable
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Reducing the Risk of Heat Illness
• Precautions for exercising in the heat
• Areas to consider
1. Environment
2. Acclimitization
3. Fitness level
4. Hydration status
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Acclimitization
• Time frame
• Fluid needs
• Sweat losses very high now
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Can it get too hot to exercise?
• Heat stress index 
Wet-Bulb-Globe Temp
WBGT
WBGT = (.1Td) + (.7Tw) + (.2Tb)
OR
WBGT = (0.3 X Ta) + (0.7 X Tw)
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WBGT Risk Chart*
*assumes light-weight clothing
WBGT
Flag Color
Level of
Risk
Comments
78° - 82°F
Green
Low
Risk on basis of
factors
82.1°-86°F
Yellow
Moderate
Limits/ high alert
86.1°-89.9°F
Red
High
> 90°F
Black
Extreme or
Hazardous
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Stop outdoor/
high alert
Reschedule/delay
High alert
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Can it get too hot to exercise?
• Tools of the trade: sling psychrometer
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Temperature & Humidity
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“HUMITURE” - VHSL RECOMMENDATION
105º and up: Recommend no outside activities.
95º to 104º:
Recommend no equipment (helmets, pads, etc)
be used during activity.
90º to 94º:
Recommend equipment be removed as often as
possible (during rest breaks, on sideline,
etc). Careful monitoring of all athletes for signs of
heat problems.
Below 89º:
Recommend adequate water supply at all
practices and competitions with breaks every 20
to 30 minutes for rehydration.
Heat Illness is Preventable
• Maintaining hydration
• Optimal fluid replacement should match
sweat loss
• Team weigh-in pre/post practices
• Team weigh-in during season
• Practice times
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ACSM Guidelines for Fluid Replacement
• Before exercise:
1. Adequate fluids during 24 hours before an event
2. Drink about 2 cups of fluid 2 hours before exercise
• Adequate/excess
• Check for hydration status
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ACSM Guidelines for Fluid Replacement
• During exercise
1. Replace sweat losses
2. Drink early & at regular intervals
3. Offer cool, flavored and/or sweetened fluids
4. Make fluid containers readily accessible
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Put more in your mouth
than on your head!
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ACSM Guidelines for Fluid Replacement
• During exercise
1. Drink 20 - 40 oz. per hour
2. 5 - 10 oz. Every 15 - 20 minutes
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Fluid Replacement
• NATA?????
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Monitor Fluid Loss After Exercise
• Goal: To replace sweat & fluid losses
completely
**150% of fluid loss to compensate for
fluids lost as urine
• Ingest carbohydrate w/in 30 minutes
• Avoid alcohol
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Monitor Fluid Balance - Practical
• Individual drink bottles
• Towel off residual sweat before weighing
• Weigh in minimal, dry clothing
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Factors Affecting Fluid
& Fuel Replacement
• Opportunities to consume fluid
• Sporting rules
• Equipment & methods to assist
fluid replacement
• Special sporting/exercise
situations
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The Ideal Fluid Replacement Beverage
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Palatability
Composition that promotes absorption
Energy content
Electrolyte content
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Fluids to Avoid While Rehydrating
• Caffeinated beverages
• Alcohol
• Carbonated beverages
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Children & Heat Stress
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Tend to absorb more heat from surroundings
Produce more heat per unit of body mass
Have a lower sweating capacity
Are less capable of transferring heat to skin for
dissipation
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Recommendations for Children
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Reduce intensity of prolonged exercise
Allow 10 - 14 days for acclimitization
Drink before exercise
Drink at least 5 oz of fluid during every 30 minutes of
exercise
• Wear appropriate,
lightweight clothing
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Athletes with Chronic Diseases
• Chronic disease can reduce or complicate an
athlete’s heat tolerance
1. Long term diabetics may have
impaired ability to sweat
2. Dehydration in the asthmatic athlete might
increase risk of attack
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Hydration Conclusions
• Heat illness is preventable with adequate hydration &
acclimitization
• Become familiar w/S/Sx of heat illness
• Know your athletes!
• Monitor your athletes
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Cold Injuries
• Predisposed athletes
• Predisposing factors
Hypothermia
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Systemic cooling of body
Cause
First sign of hypothermia
Degrees of hypothermia
– Slight
– Mild
– severe
Characteristics of hypothermia
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Gradual onset
Dilated pupils
Slow, weak pulse
Blood pressure drop (hypotension)
Shallow & irregular breathing
Muscular function
– Slight
– Mild
– Severe
• Mental status
– Slight
– Mild
– Severe
Frostbite
• Exposure to subfreezing temperatures
• Vascular physiology
• Superficial
• Deep
Preventing cold injuries
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Know the conditions
Cover skin
Wear multiple layers
Diet
NCAA Guidelines
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Layered clothing
Cover the head
Protect the hands
Stay dry
Stay hydrated
Warm thoroughly
Warm incoming air
Avoid alcohol & drugs
Never train alone
Calculating the wind chill factor
Next time…..
• Epidemiology!!!!!
4/8/2015
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