Chapter 21Heat-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, damage to the brain and other vital organs will result.

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.

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

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.

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

Electrolyte Loss

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

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

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.

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

Who Is at Risk?

• Certain medications predispose to heat stroke− Those that alter sweat production− Those that interfere with thermoregulation

Heat Illnesses

• Include a range of disorders• Only heat stroke is life threatening.

− Untreated people always die.

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

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.

Heat Exhaustion: What to Look For

• Sweating• Thirst• Fatigue• Flulike symptoms

• Shortness of breath

• Rapid heart rate

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.

Heat Stroke

• Classic heat stroke can take days to develop.

• Exertional heat stroke has a rapid onset.

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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.

Heat Stroke: What to Look For

• Extremely hot skin when touched− Usually dry

• Altered mental status

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.

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.

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.

Heat Syncope: What to Look For

• Dizziness or fainting that occurs immediately after strenuous physical activity in a hot environment

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.

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.

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.

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

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.