Lesson 13:
Heat Related Illnesses
Emergency Reference Guide p. 59-64
Objectives
• Define heat exhaustion, heat stroke &
hyponatremia
• Describe prevention techniques
• List signs/symptoms for heat related
illnesses
• Describe emergency treatment
• Describe situations that require
emergency evacuation
Heat Related Illnesses
Overview
• Range of problems associated with very warm to
hot air temperatures
• Other factors involved:
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Humidity
Being overweight/out of shape
Very young or very old
Unaccustomed to heat
Certain drugs such as antihistamines
Continued exercise
Dehydration
Heat Related Illnesses
Overview (cont’d.)
• Heat exhaustion: result of combination of
factors.
– Heat stress
– Water/electrolyte loss
– Inadequate hydration
• Heat stroke: when core produces heat faster
than it can be dissipated.
– Over-exerting or dehydrated
• Hyponatremia: low blood sodium level. Caused
by drinking too much water or failing to eat
Preventing Heat Related
Illnesses
• What can you do to prevent heat related
illnesses?
– Stay well hydrated, consume water prior to exercising
& during exercise
– Wear baggy, loosely woven clothing to allow
evaporation
– Keep head covered & face shaded
– Keep fit, start slowly
– Avoid exercise during hottest part of day
– Drugs may increase risk
– Rest in shade often
Signs/Symptoms
for Heat Exhaustion
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Sweating
Tiredness & feeling lethargic
Skin appears pale & sweaty or flushed
Headache
Nausea, sometimes vomiting
Muscle cramps
Thirst/decrease urine output
Dizziness
Elevated heart rate
Possible slight increase in core temp
Caring for Heat Exhaustion
• Stop activity, rest in cool/shady area
• Replace lost fluids:
– Quart of water with pinch salt added. Drink over a 20
minute period
– Do not use salt tablets, too concentrated
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Wet the patient down
Gently stretch & massage cramped muscles
Allow drowsy patient to sleep
Recovery may take 24 hours
When patient feels ok, allow to continue
Signs/Symptoms for Heat
Stroke
• Core temperature rising to 105F
• Disorientation, bizarre personality
changes
• Skin turning hot and red, may be dry
• Elevated heart and respiratory rate
• Headache
• Seizures
Care for Heat Stroke
• True emergency, rapid cooling is essential
– Remove from hot environment
– Remove heat retaining clothing
– Immerse in cool water or drench in cool/cold
water
• Concentrate cooling on head & neck
• Use cold packs on neck, armpits, groin, hands,
feet
• Fan patient to increase evaporation
Care for Heat Stroke (cont’d.)
• Monitor patient closely & cease cooling efforts
when normal status returns
• Give cold water to drink, if patient can accept it
• Do not give fever reducing drugs
• Have patient see health care provider as soon
as possible
• Keep careful watch on patient, relapses common
Signs/Symptoms for
Hyponatremia
• Appears to have heat exhaustion, but giving
more water makes it worse
• Also called “water intoxication”
• Looks like heat exhaustion, but:
– Urinated recently, urine clear
– Claims drinking all day, denies being thirsty
• Headache
• Weakness & fatigue
• Light headedness
Signs/Symptoms for
Hyponatremia (cont’d.)
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Muscle cramps
Nausea with/without vomiting
Sweaty skin
Normal core temp
Normal/slightly elevated pulse/respiration rate
Increasing level of anxiety
More severe symptoms include disorientation,
irritability, combativeness
• If untreated, can lead to seizures, coma & death
Caring for Hyponatremia
• Mild to moderate cases can be cared for in the
field
• Rest in shaded area
• Eat salty foods. Do not let them drink anything
• If patient is well hydrated, restricting fluid intake
is harmless
• Once patient has normal hunger/thirst and
normal urine output, the condition is resolved
Scenarios
• A 24 yr old, slightly overweight, competing
in short distance tri-athalon. Says he drank
3 - 4 quarts water. Stumbling while running
up a hill & stops at your first aid station
Scenarios
• A 68 yr old woman in excellent condition is
working on wilderness survey. She is
sweating while carrying camera equipment
then becomes confused & vomits
Guidelines for Evacuation
• GO SLOW for patient who does not fully
recover from heat exhaustion or mild
hyponatremia
• GO FAST for patient with altered mental
state due to heat related issues,
hyponatremia or experiences seizures
Questions???
What else could you add to your
First Aid Kit?