first aid

1. Chapter 21
Heat-Related Emergencies

2. How the Body Stays Cool
• The body is constantly trying to remain
cool and disperse the heat that it
produces.
• If you do not rid your body of excess heat
fast enough, damage to the brain and
other vital organs will result.

3. Disposing of Excess Heat
• Evaporation
− Sweat
• Radiation
− The body releases heat into its surroundings
when air temperature is 70°F or less.
− As environmental temperature approaches
the body’s temperature, heat loss through
radiation is reduced.

4. Water Loss
• Water makes up about 50% to 60% of an
adult’s body weight.
• About 2 quarts of water are lost daily
through:
− Breathing
− Urinating
− Bowel movements
− Sweat

5. Water Loss
• An adult requires about 2 quarts a day.
• A working adult can produce 2 to 3 quarts
of sweat an hour.
• When you are thirsty, you are already
dehydrated.

6. Dehydration
• Monitor urine output.
• While working outside in hot weather, drink
8 ounces of water every 20 minutes.
• Avoid:
− Caffeinated or alcoholic beverages
− Soda
− Fruit juices

7. Electrolyte Loss
• Potassium and sodium are essential
electrolytes.
− Found in sweat and urine
− Control movement of water in and out of cells

8. Water Intoxication
• Drinking more than 1 quart of water an
hour
• Profuse sweating for long periods
• Electrolytes are flushed from the body.
• Symptoms include:
− Frequent urination
− Behavior changes

9. Effects of Humidity
• Sweat can cool the body if it evaporates.
− Cannot evaporate in high humidity.
• At about 75% humidity, sweating is
ineffective.
• The higher the humidity, the lower the
temperature at which heat risk begins.

10. Who Is at Risk?
• Obese people
• People with
chronic illness
• People with
alcoholism
• Older people
• Infants and young
children
• Children and pets
left in parked cars
• Outdoor laborers
and athletes

11. Who Is at Risk?
• Certain medications predispose to heat
stroke
− Those that alter sweat production
− Those that interfere with thermoregulation

12. Heat Illnesses
• Include a range of disorders
• Only heat stroke is life threatening.
− Untreated people always die.

13. Heat Cramps: What to Look For
• Painful muscle spasms
• Affect the muscles in the back of the leg or
abdomen
• Happen suddenly during or after physical
exertion

14. Heat Cramps: What to Do
• Have the person rest in a cool place.
• Have the person drink lightly salted, cool
water or commercial sports drink.
• Stretch the cramped muscle.
• Pinch the upper lip just below the nose.

15. Heat Exhaustion:
What to Look For
• Sweating
• Thirst
• Fatigue
• Flulike symptoms
• Shortness of
breath
• Rapid heart rate

16. Heat Exhaustion: What to Do
• Move person to a cool place.
• Remove excess clothing.
• Spray or douse person with cold water.
• If person is able to swallow:
− Give a commercial sports drink, fruit juice,
lightly salted water, or cold water.
• Call 9-1-1 if no improvement.

17. Heat Stroke
• Classic heat stroke can take days to
develop.
• Exertional heat stroke has a rapid onset.
© Jones & Bartlett Learning.

18. Heat Stroke vs. Heat Exhaustion
• Suspect heat stroke if:
− Person’s body feels extremely hot.
− Person’s mental behavior is altered.
− A coma occurs in less than an hour
• Rectal temperature can also distinguish
heat stroke from heat exhaustion.

19. Heat Stroke: What to Look For
• Extremely hot skin when touched
− Usually dry
• Altered mental status

20. Heat Stroke: What to Do
• Move the person to a cool, shaded area.
• Remove clothing down to the person’s
underwear.
• Cool the person quickly by any means
possible.

21. Heat Stroke: What to Do
• Whole-body cold
water immersion
• Evaporative cooling
• Place ice packs
against person’s
armpits, groin, and
sides of neck.
© Jones & Bartlett Learning.

22. Heat Stroke: What to Do
• Stop cooling when the person’s mental
status improves.
• Monitor the person frequently.
• Call 9-1-1 as soon as possible.

23. Heat Syncope: What to Look For
• Dizziness or fainting that occurs
immediately after strenuous physical
activity in a hot environment

24. Heat Syncope: What to Do
• If unresponsive, check breathing.
• If person fell, check for injuries.
• Have person rest in a cool area.
• Wet skin with cool cloth or spray bottle.
• Give lightly salted cool water or a
commercial sports drink.

25. Heat Edema
• What to look for:
− Swollen ankles and feet that occur during the
first few days in a hot environment
• What to do:
− Have person wear support stockings.
− Elevate person’s legs.

26. Heat Rash
• What to look for:
− Itchy rash on skin wet from sweating
− Seen in humid regions after prolonged
sweating
• What to do:
− Dry and cool the person’s skin.
− Limit heat exposure.

27. Hyponatremia: What to Look For
• The person drank too much water.
• Frequent urination; urine is clear.
• Profuse sweating for long periods
• Dizziness, weakness, nausea, vomiting,
headache
• Altered mental status
• Seizures or unresponsiveness

28. Hyponatremia: What to Do
• Move the person to a cool location.
• Do not give more fluids.
• Give salty foods.
• For a person with altered mental status,
call 9-1-1 as soon as possible.