Extreme Heat
A Prevention Guide to Promote Your Personal Health
and Safety
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Heat-related deaths and illness are preventable yet annually many
people succumb to extreme heat. Historically, from 1979 to 1999,
excessive heat exposure caused 8,015 deaths in the United States.
During this period, more people in this country died from extreme heat
than from hurricanes, lightning, tornadoes, floods, and earthquakes
combined. In 2001, 300 deaths were caused by excessive heat exposure.
People suffer heat-related illness when their bodies are unable to
compensate and properly cool themselves. The body normally cools
itself by sweating. But under some conditions, sweating just isn't
enough. In such cases, a person's body temperature rises rapidly. Very
high body temperatures may damage the brain or other vital organs.
Several factors affect the body's ability to cool itself during
extremely hot weather. When the humidity is high, sweat will not
evaporate as quickly, preventing the body from releasing heat quickly.
Other conditions related to risk include age, obesity, fever,
dehydration, heart disease, mental illness, poor circulation, sunburn,
and prescription drug and alcohol use.
Because heat-related deaths are preventable, people need to be
aware of who is at greatest risk and what actions can be taken to
prevent a heat-related illness or death. The elderly, the very young,
and people with mental illness and chronic diseases are at highest
risk. However, even young and healthy individuals can succumb to heat
if they participate in strenuous physical activities during hot
weather. Air-conditioning is the number one protective factor against
heat-related illness and death. If a home is not air-conditioned,
people can reduce their risk for heat-related illness by spending time
in public facilities that are air-conditioned.
Summertime activity, whether on the playing field or the
construction site, must be balanced with measures that aid the body's
cooling mechanisms and prevent heat-related illness. This pamphlet
tells how you can prevent, recognize, and cope with heat-related
health problems.
What Is Extreme Heat?
Temperatures that hover 10 degrees or more above the average high
temperature for the region and last for several weeks are defined as
extreme heat. Humid or muggy conditions, which add to the discomfort
of high temperatures, occur when a "dome" of high atmospheric pressure
traps hazy, damp air near the ground. Excessively dry and hot
conditions can provoke dust storms and low visibility. Droughts occur
when a long period passes without substantial rainfall. A heat wave
combined with a drought is a very dangerous situation.
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During Hot Weather
To protect your health when temperatures are extremely high,
remember to keep cool and use common sense. The following tips are
important:
Drink Plenty of Fluids
During hot weather you will need to increase your
fluid intake, regardless of your activity level. Don't wait until
you're thirsty to drink. During heavy exercise in a hot environment,
drink two to four glasses (16-32 ounces) of cool fluids each hour.
Warning: If your doctor generally
limits the amount of fluid you drink or has you on water pills, ask
how much you should drink while the weather is hot.
Don't drink liquids that contain caffeine, alcohol,
or large amounts of sugar—these actually cause you to lose more body
fluid. Also avoid very cold drinks, because they can cause stomach
cramps.
Replace Salt and Minerals
Heavy sweating removes salt and minerals from the
body. These are necessary for your body and must be replaced. If you
must exercise, drink two to four glasses of cool, non-alcoholic fluids
each hour. A sports beverage can replace the salt and minerals you
lose in sweat. However, if you are on a low-salt diet, talk with your
doctor before drinking a sports beverage or taking salt tablets.
Wear Appropriate Clothing and
Sunscreen
Wear as little clothing as possible when you are at
home. Choose lightweight, light-colored, loose-fitting clothing.
Sunburn affects your body's ability to cool itself and causes a loss
of body fluids. It also causes pain and damages the skin. If you must
go outdoors, protect yourself from the sun by wearing a wide-brimmed
hat (also keeps you cooler) along with sunglasses, and by putting on
sunscreen of SPF 15 or higher (the most effective products say "broad
spectrum" or "UVA/UVB protection" on their labels) 30 minutes prior to
going out. Continue to reapply it according to the package directions.
Schedule Outdoor Activities
Carefully
If you must be outdoors, try to limit your outdoor
activity to morning and evening hours. Try to rest often in shady
areas so that your body's thermostat will have a chance to recover.
Pace Yourself
If you are not accustomed to working or exercising
in a hot environment, start slowly and pick up the pace gradually. If
exertion in the heat makes your heart pound and leaves you gasping for
breath, STOP all activity. Get into a cool area or at least into the
shade, and rest, especially if you become lightheaded, confused, weak,
or faint.
Stay Cool Indoors
Stay indoors and, if at all possible, stay in an
air-conditioned place. If your home does not have air conditioning, go
to the shopping mall or public library—even a few hours spent in air
conditioning can help your body stay cooler when you go back into the
heat. Call your local health department to see if there are any
heat-relief shelters in your area. Electric fans may provide comfort,
but when the temperature is in the high 90s, fans will not prevent
heat-related illness. Taking a cool shower or bath or moving to an
air-conditioned place is a much better way to cool off. Use your stove
and oven less to maintain a cooler temperature in your home.
Use a Buddy System
When working in the heat, monitor the condition of
your co-workers and have someone do the same for you. Heat-induced
illness can cause a person to become confused or lose consciousness.
If you are 65 years of age or older, have a friend or relative call to
check on you twice a day during a heat wave. If you know someone in
this age group, check on them at least twice a day.
Monitor Those at High Risk
Although any one at any time can suffer from
heat-related illness, some people are at greater risk than others.
- Infants and children up to four years of age are sensitive to
the effects of high temperatures and rely on others to regulate
their environments and provide adequate liquids.
- People 65 years of age or older may not compensate for heat
stress efficiently and are less likely to sense and respond to
change in temperature.
- People who are overweight may be prone to heat sickness because
of their tendency to retain more body heat.
- People who overexert during work or exercise may become
dehydrated and susceptible to heat sickness.
- People who are physically ill, especially with heart disease or
high blood pressure, or who take certain medications, such as for
depression, insomnia, or poor circulation, may be affected by
extreme heat.
Visit adults at risk at least twice a day and
closely watch them for signs of heat exhaustion or heat stroke.
Infants and young children, of course, need much more frequent
watching.
Adjust to the Environment
Be aware that any sudden change in temperature, such
as an early summer heat wave, will be stressful to your body. You will
have a greater tolerance for heat if you limit your physical activity
until you become accustomed to the heat. If you travel to a hotter
climate, allow several days to become acclimated before attempting any
vigorous exercise, and work up to it gradually.
Use Common Sense
Remember to keep cool and use common sense:
- Avoid hot foods and heavy meals—they add heat to your body.
- Drink plenty of fluids and replace salts and minerals in your
body.
- Dress infants and children in cool, loose clothing and shade
their heads and faces with hats or an umbrella.
- Limit sun exposure during mid-day hours and in places of
potential severe exposure such as beaches.
- Do not leave infants, children, or pets in a parked car.
- Provide plenty of fresh water for your pets, and leave the water
in a shady area.
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Hot Weather Health Emergencies
Even short periods of high temperatures can cause serious health
problems. Doing too much on a hot day, spending too much time in the
sun or staying too long in an overheated place can cause heat-related
illnesses. Know the symptoms of heat disorders and overexposure to the
sun, and be ready to give first aid treatment.
Heat Stroke
Heat stroke occurs when the body is unable to
regulate its temperature. The body's temperature rises rapidly, the
sweating mechanism fails, and the body is unable to cool down. Body
temperature may rise to 106°F or higher within 10 to 15 minutes. Heat
stroke can cause death or permanent disability if emergency treatment
is not provided.
Recognizing Heat Stroke
Warning signs of heat stroke vary but may include the
following:
- An extremely high body temperature (above 103°F, orally)
- Red, hot, and dry skin (no sweating)
- Rapid, strong pulse
- Throbbing headache
- Dizziness
- Nausea
- Confusion
- Unconsciousness
What to Do
If you see any of these signs, you may be dealing
with a life-threatening emergency. Have someone call for immediate
medical assistance while you begin cooling the victim. Do the
following:
- Get the victim to a shady area.
- Cool the victim rapidly using whatever methods you can. For
example, immerse the victim in a tub of cool water; place the person
in a cool shower; spray the victim with cool water from a garden
hose; sponge the person with cool water; or if the humidity is low,
wrap the victim in a cool, wet sheet and fan him or her vigorously.
- Monitor body temperature, and continue cooling efforts until the
body temperature drops to 101-102°F.
- If emergency medical personnel are delayed, call the hospital
emergency room for further instructions.
- Do not give the victim fluids to drink.
- Get medical assistance as soon as possible.
Sometimes a victim's muscles will begin to twitch
uncontrollably as a result of heat stroke. If this happens, keep the
victim from injuring himself, but do not place any object in the mouth
and do not give fluids. If there is vomiting, make sure the airway
remains open by turning the victim on his or her side.
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Heat Exhaustion
Heat exhaustion is a milder form of heat-related
illness that can develop after several days of exposure to high
temperatures and inadequate or unbalanced replacement of fluids. It is
the body's response to an excessive loss of the water and salt
contained in sweat. Those most prone to heat exhaustion are elderly
people, people with high blood pressure, and people working or
exercising in a hot environment.
Recognizing Heat Exhaustion
Warning signs of heat exhaustion include the
following:
- Heavy sweating
- Paleness
- Muscle cramps
- Tiredness
- Weakness
- Dizziness
- Headache
- Nausea or vomiting
- Fainting
The skin may be cool and moist. The victim's pulse rate will be
fast and weak, and breathing will be fast and shallow. If heat
exhaustion is untreated, it may progress to heat stroke. Seek medical
attention immediately if any of the following occurs:
- Symptoms are severe
- The victim has heart problems or high blood pressure
Otherwise, help the victim to cool off, and seek medical attention
if symptoms worsen or last longer than 1 hour.
What to Do
Cooling measures that may be effective include the
following:
- Cool, nonalcoholic beverages, as directed by your physician
- Rest
- Cool shower, bath, or sponge bath
- An air-conditioned environment
- Lightweight clothing
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Heat Cramps
Heat cramps usually affect people who sweat a lot
during strenuous activity. This sweating depletes the body's salt and
moisture. The low salt level in the muscles causes painful cramps.
Heat cramps may also be a symptom of heat exhaustion.
Recognizing Heat Cramps
Heat cramps are muscle pains or spasms—usually in the
abdomen, arms, or legs—that may occur in association with strenuous
activity. If you have heart problems or are on a low-sodium diet, get
medical attention for heat cramps.
What to Do
If medical attention is not necessary, take these
steps:
- Stop all activity, and sit quietly in a cool place.
- Drink clear juice or a sports beverage.
- Do not return to strenuous activity for a few hours after the
cramps subside, because further exertion may lead to heat exhaustion
or heat stroke.
- Seek medical attention for heat cramps if they do not subside in
1 hour.
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Sunburn
Sunburn should be avoided because it damages the
skin. Although the discomfort is usually minor and healing often
occurs in about a week, a more severe sunburn may require medical
attention.
Recognizing Sunburn
Symptoms of sunburn are well known: the skin becomes
red, painful, and abnormally warm after sun exposure.
What to Do
Consult a doctor if the sunburn affects an infant
younger than 1 year of age or if these symptoms are present:
- Fever
- Fluid-filled blisters
- Severe pain
Also, remember these tips when treating sunburn:
- Avoid repeated sun exposure.
- Apply cold compresses or immerse the sunburned area in cool
water.
- Apply moisturizing lotion to affected areas. Do not use salve,
butter, or ointment.
- Do not break blisters.
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Heat Rash
Heat rash is a skin irritation caused by excessive
sweating during hot, humid weather. It can occur at any age but is
most common in young children.
Recognizing Heat Rash
Heat rash looks like a red cluster of pimples or
small blisters. It is more likely to occur on the neck and upper
chest, in the groin, under the breasts, and in elbow creases.
What to Do
The best treatment for heat rash is to provide a
cooler, less humid environment. Keep the affected area dry. Dusting
powder may be used to increase comfort, but avoid using ointments or
creams—they keep the skin warm and moist and may make the condition
worse.
Treating heat rash is simple and usually does not require medical
assistance. Other heat-related problems can be much more severe.
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