Cold Stress (Hypothermia) And Heat Stress
Special Report On Cold Stress (Hypothermia)
And Heat Stress
from Bonnie Guiton
Special Adviser to the President for Consumer Affairs
and Director, U.S. Office of Consumer Affairs
COLD STRESS (HYPOTHERMIA)
Much like high blood pressure, hypothermia can be called a "silent killer" in the sense that many
of its victims are not aware of the threat. In the case of hypothermia, elderly persons may not be
aware they are becoming cold as readily as younger people, and their bodies may not adjust to changes
Others who are susceptible include individuals who (1) live alone or in isolated areas (particularly
if they don't have access to nearby phones to reach help in case of accident or illness); (2) do not
shiver or react to cold; and (3) take certain medications that prevent the body from regulating
temperatures normally, such as anti-depressants, sedatives, tranquilizers, and cardiovascular drugs.
Drugs deserve special mention because they are thought to be a major predisposing factor to
hypothermia in older adults, who, while comprising little more than 10 percent of the population,
consume 25 percent of the nation's prescription drugs. Check with a doctor or pharmacist for
information on other drugs that increase susceptibility to hypothermia.
|Hypothermia (literally "low-heat") is a condition marked by an abnormally low internal
body temperature. It develops when body heat is lost to a cool or cold environment faster than it
can be replaced. Temperatures do not have to be below freezing for hypothermia to occur, especially
in vulnerable individuals. Many older adults can develop a low body temperature after exposure to
conditions of mild cold, which would only produce discomfort in younger people.|
Who Is At Risk?
Although older adults are more vulnerable to hypothermia than younger members of the population,
infants under one year are also particularly susceptible. Among the elderly, those most likely to
develop hypothermia are the sick, the frail, the very old, the poor who can't afford enough heat,
and those medically vulnerable individuals who do not know how to keep warm when exposed to the cold.
Hypothermia can cause illness and death. Although there are no accurate data on the number of elderly
persons dying of this condition, it is estimated that about 10 percent of all persons over 65 have some
sort of temperature-regulating defect, and between three and four percent of all hospital patients over
65 are hypothermic. The National Institute on Aging (NIA) estimates that over 2.5 million older
Americans are especially vulnerable to hypothermia, and Dr. Richard Besdine of the Harvard Medical
School estimates that 25,000 older adults may die from hypothermia each year in the United States.
Click here for nutrition table for 7,248 foods.
What You Can Do
To avoid being harmed by hypothermia, now that cold weather has come to many parts of the United States,
here is some practical advice:
What To Look For
- If you live alone, arrange for a daily check-in call with a friend, neighbor, relative, etc
- Insulate your home properly Caulking is a particularly low-cost and effective technique
- Wear warm clothing Instead of tight clothing, wear several loose, warm layers Wear a hat
and scarf to avoid significant heat loss through your head and neck Stay dry Moisture from
perspiration, rain, or melting snow can seriously reduce or destroy the insulating value of
clothing because water conducts body heat over 25 times faster than air
- Use extra blankets because hypothermia can develop during sleep
- Eat nutritious foods and exercise moderately; proper diet and physical conditioning help
protect you against abnormal heat and cold
- Get proper rest; fatigue makes you more vulnerable to subnormal heat and cold
- Drink adequate amounts of liquids, such as water Limit your alcohol intake because alcohol
speeds up body heat loss
Some people die of hypothermia because they or those around them do not recognize the symptoms.
Here are some signs to watch for:
Note: Keep in mind that these signs do not necessarily mean a person is suffering from hypothermia;
they are listed to alert you to the possibility.
- Muscles: The muscles are often unusually stiff, particularly in the neck, arms, and legs
This stiffness may be accompanied by a fine trembling, perhaps limited to only one side of the
body or one arm or leg
- Shivering: Shivering is a sign that the body is having trouble keeping warm The shivering
response is frequently diminished or absent in older adults, and the fact that an older person is
not shivering in a cool or cold environment does not GUARANTEE that the person is not cold
- Face: The face is frequently puffy or swollen, and this can be an important sign, especially
when found in combination with cold skin and signs of confusion
- Coordination: The person often has difficulty walking and has problems with balance Look
for poor coordination and jerky movements
- Breathing and Heart Rate: Both are slowed at low body temperatures, and may be very difficult
to detect in severe hypothermia
- Skin: The skin is cool or cold Pay special attention to the stomach, lower back, arms, legs,
hands, and feet The skin color is usually very pale, but it may also have large, irregular blue
or pink spots
- Consciousness: As the body cools, consciousness is depressed Some hypothermia victims will
still be conscious when their body temperatures are as low as 80 degrees Remember, though, that
"conscious" and "mental clarity" are two different things A person can be "conscious and reactive"
and yet still be in a confused, disoriented, and hypothermic state, so the level of consciousness
is not always a reliable indicator of the victim's condition
- Confusion: One of the first changes brought on by hypothermia is a growing mental confusion,
which becomes progressively worse as body temperature falls Logical thinking becomes impossible and
the person may become completely disoriented Memory is affected and familiar things are often
- Attitude: Apathy is common Often the person doesn't care what happens and will do nothing
to help reduce the danger; he or she may behave strangely, or become irritable, hostile, mean, and
What To Do:
If you believe someone may be a victim of hypothermia, call an ambulance or rescue squad immediately.
Hypothermia is a dangerous, complicated medical problem and the victim needs professional attention.
However, before help arrives, here are some suggestions:
- Be very careful in handling the person Failure to do so can cause sudden death because the
heart is very weak when the body is cold
- Insulate the victim with available covering such as blankets, towels, pillows, scarves or
- Some steps can worsen a victim's condition:
- Do not attempt to rewarm the victim at home Hot baths, electric blankets, and hot water
bottles can be dangerous
- Do not give the victim any food or drink
- If the victim is unconscious, do not raise the feet This will cause blood from the legs
to flow into the body "core" and further depress the body temperature
"Energy issues are truly life and death issues for the elderly. The ultimate risk is death from
hypothermia or heat stress," said Virginia H. Knauer at last winter's energy conference of utility,
consumer, senior citizen, and energy public interest groups.
According to the Center for Environmental Physiology, the body needs time to adjust to hot weather.
A sudden increase in temperature, especially at this time of year, is particularly serious because it
can place a dangerous strain on the heart and blood vessels before the body can acclimate itself.
Heat stress, which can lead to heat exhaustion, heart failure, and strokes, may well be a life
threatening problem for the elderly this summer. Remember, the blistering heat during the summer
of 1980 claimed several thousand more lives than during previous years. The death toll was highest
among people over 65. This Special Report describes warning signs and offers precautions that may
avert the recurrence of problems for the elderly, similar to those encountered in 1980.
The elderly are more vulnerable to heat stress than younger people because they do not adjust as well
to heat. They perspire less. They are also more likely to have health problems requiring medicines
that work against the body's natural defenses to adjust to heat. For example, diuretics (often
prescribed for high blood pressure, a common disease of the elderly) prevent the body from storing
fluids and restrict the opening of blood vessels near the skin's surface. Certain tranquilizers and
drugs used to treat Parkinson's disease interfere with perspiring. These and other chronic conditions
(such as circulatory problems, diabetes, a previous stroke, overweight, and a weak or damaged heart)
often upset normal body responses.
Early symptoms - feeling hot, uncomfortable, and listless - are mild and usually pose no threat unless
they persist. However, because the serious signs of heat stress listed below are usually preceded by
the milder ones, it is important that you get medical attention if you experience any of the following:
NOTE: These symptoms can also signal other major problems, such as heart failure. Again, if you
experience any of them, call a doctor immediately.
- Rapid heartbeat
- Throbbing headache
- Dry skin (no sweating)
- Chest pain
- Great weakness
- Mental changes
- Breathing problems
The best advice for avoiding heat stress is to keep as cool as possible. So if you are up in years
or have a loved one who faces a special risk from heat stress, this information may help you avoid
- Air conditioning can provide lifesaving relief from heat stress, especially if you have
heart disease If you don't have air conditioning, spend as much time as possible in cool shopping
malls, senior centers, libraries, movie theaters, or in the coolest room in your home
- Fans can draw cool air into your home at night or help to circulate indoor air during the day
Air movement reduces heat stress by removing extra body heat
- Cool baths or showers provide relief from the heat because water removes extra body heat 25
times faster than cool air Placing ice bags or wet towels on the body is also helpful
- Loose fitting, lightweight, light colored clothing is more comfortable in hot weather Hats
and umbrellas protect your head and neck when you are outdoors
- Your body needs more water in hot weather Don't wait until you are thirsty to have a drink
If you have a disease, a medical condition, or a problem with body water balance, CHECK WITH YOUR
DOCTOR for advice on how much water you should drink
- Curtail physical activity during extremely hot weather Activity adds to heart strain
- Avoid hot foods and heavy meals They add heat to your body
- Watch salt use Check with your doctor before increasing the amount of salt or potassium
in your diet Don't take salt tablets without your doctor's permission
- Avoid alcohol Alcohol acts as a diuretic, resulting in fast water loss In addition,
alcohol can promote a sense of well-being, making you less aware of the danger signs of heat stress
- If you live alone, make sure a relative or neighbor checks on you regularly
- Take the heat seriously, pay attention to the danger signs and call your doctor at the
first sign of trouble
FOR MORE INFORMATION
This Special Report is based on information furnished by the National Institute on Aging; and the
Center for Environmental Physiology, a non-profit organization which conducts research and develops
educational programs about heat and cold stress with particular emphasis on the needs of older
Additional information can be found in your local library, public health agencies, energy offices,
and Area Agencies on Aging. Check your telephone directory's white pages under U.S. Government for
the address and telephone number.
Permission to reproduce this Special Report is granted.