Heat (Heat Wave)
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Why Talk About Extreme Heat?
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Heat can kill by pushing the human body beyond its limits.
normal conditions, the body's internal thermostat produces perspiration
that evaporates and cools the body. However, in extreme heat and high
evaporation is slowed and the body must work extra hard to maintain a
temperature. Elderly people, young children, and those who
or overweight are more likely to become victims of extreme heat.
men sweat more than women, they are more susceptible to heat illness
they become more quickly dehydrated.
The duration of excessive heat plays an important role in how
are affected by a heat wave. Studies have shown that a
in heat-related illnesses happens when excessive heat lasts more than
days. Spending at least two hours per day in air conditioning
cuts down on the number of heat-related illnesses.
What is Extreme Heat?
The parameters of an extreme heat watch, warning, or advisory
by location. Generally, temperatures that hover 10 degrees
above the average high temperature for the region, last for prolonged
of time, and are often accompanied by high humidity, that the body
tolerate are defined as extreme heat. A heat wave is a very dangerous
People living in urban areas may be at greater risk
from the effects
of a prolonged heat wave than people living in rural regions. An
health problem, especially for those with respiratory difficulties, can
occur when stagnant atmospheric conditions trap pollutants in urban
thus adding unhealthy air to excessively hot temperatures. In addition,
asphalt and concrete store heat longer and gradually releases heat at
which produces significantly higher nighttime temperatures in urban
known as the "urban heat island effect."
Learn about the risk of extreme heat in your area
your local emergency management office, National Weather Service
Know these terms:
- Heat wave: Prolonged period of
often combined with
excessive humidity. The
Service steps up its procedures to alert the public during
when it anticipates an increase in human heat-related illnesses.
- Heat index: A number in degrees
that tells how h
ot it really feels when relative humidity is added to the actual air
Exposure to full sunshine can increase the heat index by 15 degrees.
- Heat cramps: Heat cramps are muscular
spasms due to heavy
exertion. Although heat cramps are the least severe, they are often the
first signal that the body is having trouble with the heat.
- Heat exhaustion: Heat exhaustion
occurs when people exercise
heavily or work in a hot, humid place where body fluids are lost
heavy sweating. Blood flow to the skin increases, causing blood flow to
decrease to the vital organs. This results in a form of mild shock. If
not treated, the victim's condition will worsen. Body temperature will
keep rising and the victim may suffer heat stroke.
- Heat stroke: Heat stroke is
The victim's temperature
control system, which produces sweating to cool the body, stops
The body temperature can rise so high that brain damage and death may
if the body is not cooled quickly.
- Sunstroke: Another term for heat
Watch for Signals
- Heat exhaustion: Cool, moist, pale, or flushed
headache; nausea or vomiting; dizziness; and exhaustion. Body
may be normal, or is likely to be rising.
- Heat stroke: Hot, red skin; changes in
rapid, weak pulse;
and rapid, shallow breathing. Body temperature can be very
as high as 105 degrees F. If the person was sweating from heavy work or
exercise, skin may be wet; otherwise, it will feel dry.
How to Treat a Heat Emergency
- Heat stroke: Heat stroke is a life-threatening
needed fast. Call 9-1-1 or your local emergency number. Move the person
to a cooler place. Quickly cool the body. Immerse victim in a cool
or wrap wet sheets around the body and fan it. Watch for signals of
problems. Keep the person lying down and continue to cool the body any
way you can. If the victim refuses water, is vomiting, or there are
in the level of consciousness, do not give anything to eat or drink.
- Heat cramps: Get the person to a
and have him or her
rest in a comfortable position. Lightly stretch the affected muscle and
replenish fluids. Give a half glass of cool water every 15 minutes. Do
not give liquids with alcohol or caffeine in them, as they can cause
dehydration, making conditions worse.
- Heat exhaustion: Get the person out
of the heat
and into a cooler
place. Remove or loosen tight clothing and apply cool, wet cloths, such
as towels or sheets. If the person is conscious, give cool water to
Make sure the person drinks slowly. Give a half glass of cool water
15 minutes. Let the victim rest in a comfortable position, and watch
for changes in his or her condition.
Plan for Extreme Heat
Develop a Family Disaster Plan. Please see the "Family
Disaster Plan" section for general family planning
your family disaster plan before summer heat is expected. Extreme heat-
specific planning should include the following:
Learn what heat hazards may occur where you are and learn
how to plan for extreme heat should it occur in your area.
areas have different risks associated with prolonged heat. Contact your
local emergency management office, National Weather Service office, or
American Red Cross chapter for information.
If you are at risk from extreme heat:
- If your home does not have air conditioning,
go to get relief from the heat during the warmest part of the day.
Schools, libraries, theaters and other community facilities often
air-conditioned refuge on the hottest days. Air conditioning provides
safest escape from extreme heat. During the 1995 Midwest heat wave,
deaths happened to people not in air conditioned locations.
- Plan changes in your daily activities to avoid
the warmest part of the day. Ill effects of heat can quickly
the healthiest people, if they perform strenuous work during the
parts of the day. Symptoms of dehydration are not easily recognized and
are often confused with other causes. Dehydration occurs fast and makes
you ill very quickly.
- Some family members may be taking medications or
that may cause poor blood circulation or reduced ability to tolerate
Discuss these concerns with a physician. A physician can
about changes to medication or other activities you can do to
relieve the effects of heat.
- Plan to check on family, friends, and neighbors
who do not
conditioning or who spend much of their time alone. Elderly
who live alone or with a working relative might need assistance on hot
days. The majority of deaths during the 1995 Midwest heat wave were
who were alone.
- Plan to wear lightweight, light-colored clothing.
Light colors will
reflect away the sun's rays more than dark colors, which absorb the
- Get training. Take an American Red
aid course to learn
how to treat heat emergencies and other emergencies. Everyone should
how to respond, because the effects of heat can happen very quickly.
- Discuss extreme heat wave with your family.
Everyone should know
what to do in the places where they spend time. Some places may not be
air conditioned or safe during a heat wave, so plan alternatives.
extreme heat ahead of time will help reduce fear and anxiety, and lets
everyone know how to respond.
Assemble a Disaster
Please see the section "Disaster
for general supplies kit information. Extreme heat-specific supplies
include the following:
- Additional water
- Disaster Suplies Kit basics.
Protect Your Property
- Install window air conditioners snugly.
spaces around air
conditioners for a tighter fit. An air conditioner with a tight fit
the windows or wall openings will make less noise and allow less hot
in from the outside.
- Make sure your home is properly insulated.
will help you to
conserve electricity and reduce your home's power demands for air
Weather-strip doors and windowsills to keep cool air inside, allowing
inside temperature to stay cooler longer.
- During a drought, conserve water by placing a
solid object, in your toilet tank to reduce the amount of water used in
- Consider keeping storm windows installed
windows can keep the heat out of a house in the summer the same way
keep the cold out in the winter.
- Check air-conditioning ducts for proper
ducts prevents cool air from leaking and keeps it directed through the
- Protect windows. Hang shades,
awnings, or louvers on
windows that receive morning or afternoon sun. Outdoor awnings or
can reduce the heat entering the house by as much as 80 percent.
- Use attic fans. If you have a fan
vent warm air out
of your attic, use the fan to help keep your home cool.
Media and Comminity Education Ideas
- Publish a special newspaper section with
information on extreme
heat. Localize the information by including the phone numbers
emergency services offices, the American Red Cross chapter, and local
- Interview local physicians about the dangers
sunburn, heat exhaustion,
heat stroke, and other possible conditions caused by excessive heat.
- During a drought, run a series of programs
can conserve water and energy in their homes and their
- Interview local officials and representatives of
Department of Agriculture about special steps
farmers can take
to establish alternative water supplies for their crops and ways to
livestock and poultry from the effects of extreme heat.
- Sponsor a "Helping Your Neighbors" program
system to encourage children to think of those persons who
special assistance during severe weather conditions, such as elderly
infants, or people with disabilities.
- Arrange for air-conditioned shelters to be opened
for community members who do not have air conditioning at home.
- Arrange for special programs to provide air
people in their homes.
What to Do During Extreme Heat
- Slow down. Avoid strenuous activity.
eliminate or reschedule
strenuous activities. High-risk individuals should stay in cool places.
Get plenty of rest to allow your natural "cooling system" to work. If
must do strenuous activity, do it during the coolest part of the day,
is usually in the morning between 4:00 a.m. and 7:00 a.m. Many heat
are experienced by people exercising or working during the hottest part
of the day.
- Avoid too much sunshine. Sunburn slows
skin's ability to cool
itself. The sun will also heat the inner core of your body, resulting
dehydration. Use a sunscreen lotion with a high sun protection factor
- Postpone outdoor games and activities.
heat can threaten
the health of athletes, staff, and spectators of outdoor games and
- Avoid extreme temperature changes. A
coming in from hot temperatures can result in hypothermia, particularly
for elderly and very young people.
- Stay indoors as much as possible. If
conditioning is not available,
stay on the lowest floor, out of the sunshine. Even in the warmest
staying indoors, out of sunshine, is safer than long periods of
to the sun.
- Keep heat outside and cool air inside.
may allow heat inside. Install temporary reflectors, such as aluminum
covered cardboard, in windows and skylights to reflect heat back
- Conserve electricity not needed to keep you cool.
of extreme heat, people tend to use a lot more power for air
Conserve electricity not used to keep you cool so power can remain
and reduce the chance of a community wide outage.
- Vacuum air conditioner filters weekly during
Air conditioner filters can become clogged or filled with dirt, making
them less efficient. Keeping them clean will allow your air conditioner
to provide more cool air.
- If your home does not have air conditioning, go
with air conditioning each day for several hours. Air
are the safest places during extreme heat because electric fans do not
cool the air. Fans do help sweat evaporate, which gives a cooling
- Dress appropriately:
- Wear loose-fitting, lightweight, light-colored
that will cover
as much skin as possible. Lightweight, light-colored clothing
heat and sunlight and helps maintain normal body temperature. Cover as
much skin as possible to avoid sunburn and over-warming effects of
on your body.
- Protect face and head by wearing a
A hat will
keep direct sunlight off your head and face. Sunlight can burn and warm
the inner core of your body.
- Drink plenty of fluids even if you do not feel
death can occur from dehydration, which can happen quickly and
Symptoms of dehydration are often confused with other causes. Persons
have epilepsy or heart, kidney, or liver disease; who are on
diets; or who have a problem with fluid retention should consult a
before increasing liquid intake.
- Take frequent breaks if you must work outdoors.
especially in a cool area or to drink fluids, can help people tolerate
- Use a buddy system when working in extreme heat.
Partners can keep
an eye on each other and can assist each other when needed. Sometimes
to heat can cloud judgment. Chances are if you work alone, you may not
- Drink plenty of water regularly and often.
body needs water
to keep cool. Water is the safest liquid to drink during heat
- Avoid drinks with alcohol or caffeine in them.
They can make you
feel good briefly, but make the heat's effects on your body worse. This
is especially true about beer, which actually dehydrates the body.
- Eat small meals and eat more often.
meals are more
difficult to digest and cause your body to increase internal heat to
digestion, worsening overall conditions. Avoid foods that are high in
such as meats and nuts, which increase metabolic heat.
- Avoid using salt tablets unless directed to do
so by a
Salt causes the body to retain fluids, resulting in swelling. Salt
areas of your body that help you sweat, which would keep you cool.
on salt-restrictive diets should check with a physician before
- NEVER leave children or pets alone in closed
inside a closed vehicle can reach over 140 degrees F within minutes.
to such high temperatures can kill in minutes.
Produced by the National
Disaster Education Coalition: American
Red Cross, FEMA,
IAEM, IBHS, NFPA, NWS, USDA/CSREES,
and USGS. HTML
formating By the
From: Talking About Disaster: Guide for Standard
by the National Disaster Education Coalition, Washington, D.C., 1999.
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