Chapter 21

Heat-Related Emergencies

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, it cooks the brain and other vital organs.

Disposing of Excess Heat• Evaporation

• Sweat• Radiation

• The body releases heat into its surroundings when the air temperature is 70˚F or less.

• As the environmental temperature approaches the body’s temperature, heat loss through radiation is reduced.

Water Loss (1 of 2)

• Water makes up about 50 to 60% of an adult’s body weight.

• About two quarts of water is lost daily through:

• Breathing• Urinating• Bowel movements• Sweat

Water Loss (2 of 2)

• An adult requires about two quarts a day.• A working adult can produce two to three

quarts of sweat an hour. • When you are thirsty, you are already

dehydrated.

Dehydration (1 of 2)

• Monitor urine output.• Enough water = clear urine at least five times

a day.• Not enough water = cloudy or dark urine less

than five times a day.• While working outside in hot weather, drink 8

ounces of water every 20 minutes.

Dehydration (2 of 2)

• Cool water is easier to absorb than warm water.

• Avoid:• Caffeinated beverages• Alcoholic beverages• Soda• Fruit juices

Electrolyte Loss• Potassium and sodium are essential

electrolytes• Found in sweat and urine • Control movement of water in and out of cells

• Sodium is not a problem in the typical American diet.

• Commercial sports drinks are useful for physical activity lasting more than one hour.

Water Intoxication• Drinking more than 1 quart of water an

hour• Profuse sweating for long periods of time• Electrolytes are flushed from the body. • Symptoms include:

• Frequent urination• Behavior changes

Effects of Humidity • Sweat can cool the body only if it

evaporates. • Sweat cannot evaporate in high humidity. • The higher the humidity, the lower the

temperature at which heat risk begins.

Who Is At Risk? (1 of 2)

• At particular risk:• Obese people• People with chronic illness• People with alcoholism• Elderly• Infants and young children• Children and pets left in parked cars• Outdoor laborers and athletes

Who Is At Risk? (2 of 2)

• Certain medications predispose to heatstroke:

• Those that alter sweat production• Those that interfere with

thermoregulation

Heat Illnesses • Include a range of disorders• Only heatstroke is life threatening.

• Untreated victims always die.

Heat CrampsHeat cramps are painful muscle spasms that

occur suddenly during or after vigorous exercise or activity.

Recognizing Heat Cramps•Painful muscle spasms that happen suddenly•Affect the muscles in the back of the leg or abdomen•Occur during or after physical exertion

Care for Heat Cramps• Have the victim rest in a cool place. • Have the victim drink lightly salted, cool

water or commercial sports drink. • Stretch the cramped calf muscle. • Place an ice bag on the painful muscle.• Pinch the upper lip just below the nose.

Heat ExhaustionHeat exhaustion is characterized by heavy

perspiration with normal or slightly above-normal body temperature.

Recognizing Heat Exhaustion• Sweating• Thirst• Fatigue• Flulike symptoms• Shortness of breath• Fast heart rate

Care for Heat Exhaustion• Move victim immediately to a cool place. • Give cool liquids. • Raise victim’s legs 6 to 12 inches. • Remove excess clothing. • Sponge victim with cool water and fan him

or her. • Place ice bags on sides of chest, neck, and

armpits. • Seek medical care if there is no

improvement within 30 minutes.

Heatstroke• Classic

heatstroke can take days to develop.

• Exertional heatstroke has a rapid onset.

Heatstroke vs. Heat Exhaustion

• Suspect heatstroke if: • Victim’s body feels extremely hot • Victim’s mental behavior is altered• A coma occurs in less than an hour

• Rectal temperature can also distinguish heatstroke from heat exhaustion.

Recognizing Heatstroke• Extremely hot skin when touched• Altered mental status

Care for Heatstroke (1 of 2)

• Move the victim immediately to a cool place.

• Remove clothing down to the victim’s underwear.

• Keep the victim’s head and shoulders slightly elevated.

• Call 9-1-1 immediately.

Care for Heatstroke (2 of 2)

• Cool the victim quickly.• Spray with water• Fan • Apply cool, wet

sheets or cloths• Apply ice bags• Place in ice bath• Place in cool bath