Transcript Heat-Related Illness Mark De Carlo, PT, MHA, SCS, ATC Methodist Sports Medicine Center Indianapolis, Indiana.

Heat-Related Illness
Mark De Carlo, PT, MHA, SCS, ATC
Methodist Sports Medicine Center
Indianapolis, Indiana
Introduction
Heat illness is inherent to physical
activity
 Heat illness incidence increases with
rising temperature and relative humidity
 Heat illness is not synonymous with
hydration status
 Heat illness deaths in football are
preventable

Traditional Philosophies
Not being able to “take the heat” is a sign
of weakness
 Restricting water as a disciplinary
measurement
 Drinking too much water causes cramps
 Salt tablets prevent cramps
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Statistics
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Annual Survey of Football Injury Research
1931-2003
– Chaired by Dr. Fred Mueller
– 106 total cases of heat stroke which resulted
in death
– 1960 to 2003 – 101 heat stroke deaths
– 1970 – high of 8 heat stroke deaths
– 1995 to 2001 – 15 of 21 heat stroke deaths at
the high school level
– 0 heat stroke deaths in past 2 years
Risk Factors
Intrinsic Risk Factors
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History of heat
illness
Poor heat acclimation
Lower fitness level
Higher % body fat
Dehydration
Fever/illness
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Medications
(diuretics,
antihistamines)
Supplements
(ephedra)
Highly motivated
Reluctance to report
problems
Extrinsic Risk Factors
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Intense and
prolonged exercise
High temperature,
humidity, and sun
exposure
Lack of education
and awareness
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No shade or rest
breaks
Limited access to
fluids
No emergency plan
Delay in recognition
of early warning signs
Prevention
Hydration
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Dehydration occurs
when sweat loss
exceeds fluid intake
Fluid-replacement
should be cold and
easily accessible
Thirst is a poor
indicator of
hydration
Hydration
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Prehydrate
– Drink 16 oz 2 hours
prior to activity
Maintain hydration
– Drink 6-8 oz for
every 15 minutes of
intense activity
Rehydrate
– Correct fluid loss
within 2 hours after
activity
Monitor Weight Loss
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Check weight before and
after activity
Match fluid intake to
sweat and urine loss
Voluntary drinking
replaces only about 50%
of body-fluid loss
Maintain less than 2%
body-weight change
Replace weight loss with
equal amount of fluid
– Drink 16 oz for each
pound lost
Electrolyte Balance
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Eat salty foods or add salt
to meals and snacks
If activity > 1 hour,
include carbohydrates
and sodium with fluid
– Sports drinks
Avoid salt tablets
– With insufficient
water, hypertonicity
can make dehydration
worse
Drugs and Supplements
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Ephedra
– Linked to heart attacks,
seizures, and heat stroke
Diuretics
– Cause loss of fluids
Antihistamines
– Constrict blood vessels
Check side effects of all
medications
Heat Acclimation
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Gradually ramp up
outdoor activity
First 2 to 3 days of
activity present
greatest danger
Acclimatization
requires 8 to 12 days
for adults, 10 to 14
days for adolescents
Clothing and Equipment
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Wear loose fitting or
moisture-wicking,
light colored clothes
Sweat dampened
clothes impede
evaporation
– Avoid cottons or
bring an extra
change of clothes
Minimize equipment
and padding when
indicated
Environment
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Wet Bulb Globe Temperature (WBGT)
– Used as an index to modify activity
– WBGT = (.1 x Dry Bulb Temp) +
(.2 x Black Globe Temp) + (.7 x Wet
Bulb Temp)
Environment
Wet-Bulb Globe Temperature
Temp
Flag
Risk
Work:Rest
< 65 F
Green
Low
4:1
65 - 73 F
Yellow Moderate
3:1
73 - 82 F
Red
High
2:1
> 82 F
Black
Extreme
1:1
Environment
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Sling psychrometer
– Can be used to estimate WBGT
– Produces dry bulb temperature (DBT)
and wet bulb temperature (WBT)
– Use DBT and WBT to calculate relative
humidity
Environment
Environment
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Modify activity under
high risk conditions
– Increase length and
frequency of rest
breaks
– Limit intensity and
duration of activity
– Limit the amount of
clothing and
equipment
– Unlimited and
accessible hydration
Recognition
Heat Illness
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Heat illness is traditionally divided into 4
categories
– Heat cramps
– Heat syncope
– Heat exhaustion
– Heat stroke
Heat illness is not sequential; there is a lack of
continuum between categories
Early recognition of heat illness is more
important than differentiating categories of
heat illness
Signs and Symptoms
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Early
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Weakness, fatigue
Weak, rapid pulse
Dizziness, light
headed, fainting
Dehydration and
cramping
Pallor
Cool and clammy skin
Profuse sweating
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Severe
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Nausea, vomiting,
diarrhea
Skin hot and wet or dry
Staggering gait
Delirium, confusion
Irrational behavior,
emotional instability,
aggressiveness
Loss of consciousness
On-Field Recognition
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Players
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Taking a knee
Cramping
Vomiting
Slow returning to
huddle or disengaged
from huddle
Going to the wrong
sideline
Staggering
Collapse
On-Field Recognition
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Officials
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Flushed or pale face
Resting hands on
knees
Altered vision
Confusion about
rules, possession,
penalties
Incoherent speech
Hyperventilation
Staggering
Collapse
Treatment
Treatment Guidelines
Heat loss must equal heat gain
 Recognize that all stages of heat illness
require treatment of fluid replacement
and cooling
 Take early action
 When in doubt, assume heat stroke
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Early Treatment
Remove from activity to shade or air
conditioned facility
 Begin fluid replacement
 Remove excess clothing and equipment
 Cool with fans, ice towels, or ice bags
 Monitor vitals and core temperature
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Severe Treatment
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Cool before transport
Remove excess clothing and equipment
Rapid, whole body cooling
– Cold water immersion for 20 minutes in
small pool or tub is best treatment
•
Ice packs to axilla and groin, cover with ice
towels, spray with cold water
Oral fluids if conscious
Monitor rectal temperature
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100% success in 252 cases of heat stroke
Recommendations for
Officials
Consult with athletic training staff prior
to contest
 Utilize official’s time out for heat and
humidity to allow extra rest and water
breaks
– Rule 3-5-1, ART 7 and Case 3.5.7
 Monitor athletes for signs and symptoms
 Practice and apply guidelines to
yourselves
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Conclusion
Heat illness death is preventable
 Modify activity under high risk
conditions
 Recognize early signs of heat illness
 All categories of heat illness require
treatment of hydrating and cooling
 Cold water immersion is the best
treatment
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