Fever
What is a normal body
temperature?
Most people have an average body temperature
of about 98.6°F (37ºC), measured with a
thermometer placed under the tongue. It is
normal for your temperature to be as low as
97.4°F (36.3ºC) in the morning or as high as
99.6°F (37.6ºC) in the late afternoon. It may go
up when you exercise, wear heavy clothes, or
take a hot bath, or during hot weather.
What is a fever temperature?
A fever is a high body temperature. It is one way
your body fights being sick. Although a fever
can be a sign that you are very ill, most fevers
are not caused by a serious problem. With a
minor illness, such as a cold, you may have a
fever. However, a very serious infection may
cause little or no fever.
In most healthy people, a fever does not in itself
require treatment other than drinking plenty of
fluids. Taking acetaminophen (Tylenol) or
ibuprofen (Advil, Motrin) may help you feel
more comfortable. Follow the package
instructions carefully. If you give medicine to
your baby, follow what your doctor has told you
about the amount to give. Do not give aspirin
to anyone younger than 20 because of the risk
of Reye syndrome, a rare but serious disease.
Talk to your doctor before you give fever
medicine to a baby who is 3 months of age or
younger. This is to make sure a young baby's
fever is not a sign of a serious illness. The
exception is if your baby has just had an
immunization. Fevers sometimes occur as a
reaction to immunizations. After immunizations,
you can give your baby fever medicine.
In most adults, an oral temperature above 100°F
(37.8ºC) or a rectal or ear temperature above
101°F (38.3ºC) is considered a fever. A child
has a fever when his or her rectal temperature
is 100.4°F (38ºC) or higher.
A temperature of up to 102°F (38.9ºC) helps the
body fight infection. Most healthy people can
have a fever as high as 103°F (39.4ºC) to 104°F
(40ºC) for short periods of time without
problems.
What can cause a fever?
A fever may be a reaction to:
• Infection. This is the most common cause
of a fever. Examples of infections that can
cause a fever include viral infections, such
as colds and flu, and bacterial infections,
such as a urinary tract infection or
pneumonia.
• Medicines, such as antibiotics,
antihistamines, opiates, and many others.
• Severe trauma or injury, such as a heart
attack, stroke, heatstroke, or burns.
• Other medical conditions, such as arthritis
and some cancers.
How should you take your
temperature?
Your body temperature can be measured in
many locations on your body.
Taking a temperature orally (in the mouth) is
the most common method. For you to get an
accurate reading, the person must be able to
breathe through the nose. If this is impossible,
choose a different method to check the
temperature.
Taking a temperature in the rectum is
recommended for babies, small children, and
people who cannot hold a thermometer safely
in their mouths. It is also used when getting the
most accurate measurement is essential. A rectal
temperature reading may be as much as 1°F
(0.6ºC) higher than an oral temperature reading.
Taking a temperature in the armpit may not
be as accurate as taking an oral or rectal
temperature. An armpit temperature reading may
be as much as 1°F (0.6ºC) lower than an oral
temperature reading.
Taking a temperature in the ear requires a
special ear thermometer. It is not inserted very
far into the ear, and it provides a reading in only
a few seconds.
Taking a temperature on the forehead with
a plastic temperature strip is less reliable than
the other methods. If your baby is younger than
3 months or your child's fever rises higher than
102°F (38.9ºC), recheck the temperature using
another method.
Do not use a glass thermometer that contains
mercury. If you have one, contact your local
health department to find out how to get rid of
it safely. Mercury is very poisonous. If you
break a glass thermometer, call your local poison
control center right away.
Taking an oral temperature
To take a temperature orally:
1.
Place the digital or disposable thermometer
under the tongue, just to one side of the
center, and close the lips tightly around it.
2.
Leave the thermometer in place for the
required amount of time. Some digital
thermometers give a series of short beeps
when the reading is done.
3.
Remove the thermometer and read it.
4.
Clean a digital thermometer with cool,
soapy water, and rinse it off before you put
it away.
Keeping a record of your
temperature
When you have a fever, check your temperature
several times each day. If you are being treated
for cancer or with certain medicines, your doctor
may want you to check your temperature at least
two times a day, even if you do not feel like you
have a fever. Write down the time and the
results. This can help you and your doctor
determine what may be causing your fever and
how best to treat your illness.
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of this information, which does not replace medical advice. 2015-05-zx1264