Most parents have experienced this scenario: You wake up in the
middle of the night to find your child standing by your bed,
flushed, hot, and sweaty. Your little one's forehead feels
warm. You immediately suspect a fever, but are unsure of what to do
next. Should you get out the thermometer? Call the doctor?
In healthy kids, fevers usually don't indicate anything
serious. Although it can be frightening when your child's
temperature rises, fever itself causes no harm and can actually be
a good thing - it's often the body's way of fighting off
infections. And not all fevers need to be treated. High fever,
however, can make a child uncomfortable and aggravate problems such
as dehydration.
But it's easy to learn how to correctly take a
child's temperature when it's a little higher than usual.
Read on for more about fevers, how to measure and treat them,
and when to call your child's doctor.
What Is Fever?
Fever occurs when the body's internal "thermostat"
raises the body temperature above its normal level. This thermostat
is found in the part of the
brain
called the
hypothalamus
. The hypothalamus knows what temperature your body should be
(usually around 98.6º Fahrenheit, or about 37º Celsius) and will
send messages to your body to keep it that way.
Most people's body temperatures even change a little bit
during the course of the day: It's usually a little lower in
the morning and a little higher in the evening and can fluctuate as
kids run around, play, and exercise.
Sometimes, though, the hypothalamus will "reset" the
body to a higher temperature in response to an infection, illness,
or some other cause. So, why does the hypothalamus tell the body to
change to a new temperature? Researchers believe turning up the
heat is the body's way of fighting the germs that cause
infections and making the body a less comfortable place for
them.
What Causes Fever?
It's important to remember that fever by itself is not an
illness - it's usually a symptom of an underlying problem.
Fever has several potential causes:
Infection:
Most fevers are caused by infection or other illness. Fever helps
the body fight infections by stimulating natural defense
mechanisms.
Overdressing:
Infants, especially newborns, may get fevers if they're
overbundled or in a hot environment because they don't regulate
their body temperature as well as older children. However, because
fevers in newborns can indicate a serious infection, even infants
who are overdressed must be evaluated by a doctor if they have a
fever.
Immunizations:
Babies and children sometimes get a low-grade fever after getting
vaccinated
.
Although teething may cause a slight rise in body temperature,
it's probably not the cause if a child's temperature is
higher than 100º Fahrenheit (37.8º Celsius).
When Can a Fever Be a Sign of Something Serious?
In the past, doctors advised treating a fever on the basis of
temperature alone. But now they recommend considering both the
temperature and the child's overall condition.
Kids whose temperatures are lower than 102º Fahrenheit (38.9º
Celsius) often don't require medication unless they're
uncomfortable. There's one important exception to this rule: If
you have an infant 3 months or younger with a rectal temperature of
100.4º Fahrenheit (38º Celsius) or higher, call your doctor or go
to the emergency department immediately. Even a slight fever can be
a sign of a potentially serious infection in very young
infants.
If your child is between 3 months and 3 years old and has a
fever of 102.2º Fahrenheit (39º Celsius) or higher, call the doctor
to see if he or she needs to see your child. For older kids, take
behavior and activity level into account. Watching how your child
behaves will give you a pretty good idea whether a minor
illness is the cause or if your child should be seen by a
doctor.
The illness is probably
not
serious if your child:
- is still interested in playing
- is eating and drinking well
- is alert and smiling at you
- has a normal skin color
- looks well when his or her temperature comes down
And don't worry too much about a child with a fever who
doesn't want to eat. This is very common with infections that
cause fever. For kids who still drink and urinate normally,
not eating as much as usual is OK.
How Do I Know if My Child Has a Fever?
A gentle kiss on the forehead or a hand placed lightly on your
child's skin is often enough to give you a hint that your
child has a fever. However, this method of taking a temperature
(called tactile temperature) is dependent on the person doing the
feeling and doesn't give an accurate measure of
temperature.
Use a reliable thermometer to tell if your child has a fever
when his or her temperature is at or above one of these
levels:
- 100.4º Fahrenheit (38º Celsius) measured rectally (in the
bottom)
- 99.5º Fahrenheit (37.5º Celsius) measured orally (in the
mouth)
- 99º Fahrenheit (37.2º Celsius) measured in an axillary
position (under the arm)
But how high a fever is doesn't tell you much about how sick
your child is. A simple cold or other viral infection can sometimes
cause a rather high fever (in the 102º-104º Fahrenheit / 38.9º-40º
Celsius range), but this doesn't usually indicate a serious
problem. And serious infections may cause no fever or even an
abnormally low body temperature, especially in infants.
Because fevers may rise and fall, a child with fever might
experience chills as the body tries to generate additional heat as
its temperature begins to rise. The child may sweat as the
body releases extra heat when the temperature starts to drop.
Sometimes kids with a fever breathe faster than usual and may
have a higher heart rate. You should call the doctor if your child
is having difficulty breathing, is breathing faster than normal, or
continues to breathe fast after the fever comes down.
Different Types of Thermometers
Whichever type of thermometer you choose, be sure you know how
to use it correctly to get an accurate reading. Keep and follow the
manufacturer's recommendations for any thermometer.
Digital thermometers
usually provide the quickest, most accurate readings. They come in
many sizes and shapes, are available at most supermarkets and
pharmacies, and are available in a range of prices. Although you
should read the manufacturer's instructions to determine what
method or methods the thermometer is designed for, many digital
thermometers can be used for the following temperature-taking
methods:
- oral (in the mouth)
- rectal (in the bottom)
- axillary (under the arm)
Digital thermometers usually have a plastic, flexible probe with
a temperature sensor at the tip and an easy-to-read digital display
on the opposite end.
Electronic ear thermometers
measure the tympanic temperature - the temperature inside the ear
canal. Although they're quick and easy to use in older babies
and children, electronic ear thermometers aren't as accurate
for infants 3 months or younger as digital thermometers and
are more expensive.
Plastic strip thermometers
(small plastic strips that you press against your child's
forehead) may be able to tell you whether your child has a fever,
but they aren't reliable for taking an exact measurement,
especially in infants and very young children. If you need to know
your child's exact temperature, plastic strip thermometers are
not
the way to go.
Forehead thermometers
also may be able to tell you if your child has a fever, but are not
as accurate as oral or rectal digital thermometers.
Pacifier thermometers
may seem convenient, but again, their readings are less reliable
than rectal temperatures and shouldn't be used in infants
younger than 3 months. They also require the child to keep the
pacifier in the mouth for several minutes without moving, which is
a nearly impossible task for most babies and toddlers.
Glass mercury thermometers
were once common, but the American Academy of Pediatrics (AAP) now
says they should not be used because of concerns about
possible exposure to mercury, which is an environmental toxin. (If
you still have a mercury thermometer, do
not
simply throw it in the trash where the mercury can leak out. Talk
to your doctor or your local health department about how and where
to dispose of a mercury thermometer.)
As any parent knows, taking a squirming child's temperature
can be challenging. But it's one of the most important tools
doctors have to determine if a child has an illness or infection.
The method you choose to take your child's temperature will
depend on his or her age and how cooperative your child is.
If your child is younger than 3 months
, you'll get the most reliable reading by using a digital
thermometer to take a rectal temperature. Electronic ear
thermometers aren't recommended for infants younger than 3
months because their ear canals are usually too small.
If your child is between 3 months to 4 years old
, you can use a digital thermometer to take a rectal temperature or
an electronic ear thermometer to take the temperature inside the
ear canal. You could also use a digital thermometer to take an
axillary temperature, although this is a less accurate method.
If your child is 4 years or older
, you can usually use a digital thermometer to take an oral
temperature if your child will cooperate. However, kids who have
frequent coughs or are breathing through their mouths because of
stuffy noses might not be able to keep their mouths closed long
enough for an accurate oral reading. In these cases, you can use
the tympanic method (with an electronic ear thermometer) or
axillary method (with a digital thermometer).
How to Use a Digital Thermometer
A digital thermometer offers the quickest, most accurate way to
take a child's temperature and can be used in the mouth,
armpit, or rectum. Before you use one, read the directions
thoroughly. You need to know how the thermometer signals that the
reading is complete (usually, it's a beep or a series of beeps
or the temperature flashes in the digital window on the front of
the thermometer).
First, turn on the thermometer and make sure the screen is clear
of any old readings. If your thermometer uses disposable plastic
sleeves or covers, put one on according to the manufacturer's
instructions. Remember to discard the sleeve after each use and to
clean the thermometer according to the manufacturer's
instructions before putting it back in its case.
To take a rectal temperature:
Before becoming parents, most people cringe at the thought of
taking a rectal temperature. But don't worry - it's a
simple process:
- Lubricate the tip of the thermometer with a lubricant, such
as petroleum jelly.
- Place your child:
- belly-down across your lap or on a firm, flat surface and
keep your palm along the lower back
- or face-up with legs bent toward the chest with your hand
against the back of the thighs
- With your other hand, insert the lubricated thermometer into
the anal opening about 1/2 inch to 1 inch (about 1.25 to 2.5
centimeters). Stop if you feel any resistance.
- Steady the thermometer between your second and third fingers
as you cup your hand against your baby's bottom. Soothe your
child and speak quietly as you hold the thermometer in
place.
- Wait until you hear the appropriate number of beeps or other
signal that the temperature is ready to be read. Write down the
number on the screen, noting the time of day that you took the
reading.
To take an oral temperature:
This process is easy in an older, cooperative child.
- Wait 20 to 30 minutes after your child finishes eating or
drinking to take an oral temperature, and make sure there's
no gum or candy in your child's mouth.
- Place the tip of the thermometer under the tongue and ask
your child to close his or her lips around it. Remind your child
not to bite down or talk, and to relax and breathe normally
through the nose.
- Wait until you hear the appropriate number of beeps or other
signal that the temperature is ready to be read. Write down the
number on the screen, noting the time of day that you took the
reading.
To take an axillary temperature:
This is a convenient way to take a child's temperature.
Although not as accurate as a rectal or oral temperature in a
cooperative child, some parents may prefer to take an axillary
temperature, especially for kids who can't hold a
thermometer in their mouths.
- Remove your child's shirt and undershirt, and place the
thermometer under an armpit (it must be touching skin only, not
clothing).
- Fold your child's arm across the chest to hold the
thermometer in place.
- Wait until you hear the appropriate number of beeps or other
signal that the temperature is ready to be read. Write down the
number on the screen, noting the time of day that you took the
reading.
Whatever method you choose, keep these additional tips in
mind:
- Never take a child's temperature right after a bath or if
he or she has been bundled tightly for a while - this can affect
the temperature reading.
- Never leave a child unattended while taking a
temperature.
Helping Kids Feel Better
Again, not all fevers need to be treated. And in most cases, a
fever should be treated only if it's causing a child
discomfort. Here are ways to alleviate symptoms that often
accompany a fever:
- If your child is fussy or appears uncomfortable, you can give
acetaminophen or ibuprofen based on the package recommendations
for age or weight. If you don't know the recommended dose or
your child is younger than 2 years, call the doctor to find out
how much to give. Remember that fever medication will usually
temporarily bring a temperature down, but it will not return it
to normal - and it won't treat the underlying reason for the
fever. (
Unless instructed by a doctor, never give aspirin to a
child
due to its association with
Reye syndrome
, a rare but potentially fatal disease.) Infants under 2 months
old should not be given any medication for fever without being
evaluated by a doctor. If your child has any medical problems,
check with the doctor to see which medication is best to
use.
- Giving a sponge bath can make your child more
comfortable and help bring the fever down. Use only lukewarm
water; cool water may cause shivering, which actually raises body
temperature.
Never
use alcohol (it can cause poisoning when absorbed through the
skin) or ice packs/cold baths (they can cause chills that may
raise body temperature).
- Dress your child in lightweight clothing and cover him or her
with a light sheet or blanket. Overdressing and overbundling can
prevent body heat from escaping and can cause a temperature to
rise.
- Make sure your child's room is a comfortable temperature
- not too hot or too cold.
- Offer plenty of fluids to avoid
dehydration
- a fever will cause a child to lose fluids more rapidly. Water,
soup, ice pops, and flavored gelatin are all good choices. Avoid
drinks containing caffeine, including colas and tea, because they
can cause increased urination.
- If your child also is vomiting and/or has
diarrhea
, ask the doctor if you should give an electrolyte (rehydration)
solution made especially for kids. You can find these solutions
at pharmacies and supermarkets. Don't offer sports drinks -
they're not designed for younger children, and the added
sugars may make diarrhea worse. Also, limit your child's
intake of fruits and apple juice.
- In general, let your child eat what he or she wants (in
reasonable amounts) but don't force eating if your child
doesn't feel like it.
- Make sure your child gets plenty of rest. Staying in bed all
day isn't necessary, but a sick child should take it
easy.
- It's best to keep a child with a fever home from
school or child care. Most doctors feel that it's safe to
return when the temperature has been normal for 24 hours.
When to Call the Doctor
The exact temperature that should trigger a call to the doctor
depends on the age of the child, the illness, and whether the child
has other symptoms with the fever.
Call your doctor if you have an:
- infant younger than 3 months with a temperature of 100.4º
Fahrenheit (38º Celsius) or higher
- older child with a temperature of higher than 102.2º
Fahrenheit (39º Celsius)
Call the doctor if an older child has a fever of
less
than 102.2º Fahrenheit (39º Celsius) but also:
- refuses fluids or seems too ill to drink adequately
- has persistent diarrhea or repeated vomiting
- has any signs of dehydration (urinating less than usual, not
having tears when crying, less alert and less active than
usual)
- has a specific complaint (i.e., sore throat or earache)
- still has a fever after 24 hours (in kids younger than 2
years) or 72 hours (in kids 2 years or older)
- has recurrent fevers, even if they only last a few hours each
night
- has a chronic medical problem such as heart disease, cancer,
lupus, or sickle cell anemia
- has a rash
- has pain with urination
Seek emergency care if your child shows any of the following
signs along with a fever:
- inconsolable crying
- extreme irritability
- lethargy and difficulty waking
- rash or purple spots that look like bruises on the skin (that
were not there before the child got sick)
- blue lips, tongue, or nails
- infant's soft spot on the head seems to be bulging
outward or sunken inwards
- stiff neck
- severe headache
- limpness or refusal to move
- difficulty breathing that doesn't get better when the
nose is cleared
- leaning forward and drooling
-
seizure
- abdominal pain
Also, ask your child's doctor for his or her specific
guidelines on when to call about a fever.
Fever: A Common Part of Childhood
All kids get fevers, and in the majority of cases, most are
completely back to normal within a few days. For older infants and
children (but not necessarily for infants younger than 3 months),
the way they act is far more important than the reading on
your thermometer. Everyone gets cranky when they have a fever. This
is normal and should be expected.
But if you're ever in doubt about what to do or what a fever
might mean, or if your child is acting ill in a way that concerns
you even if there's no fever, always call your doctor for
advice.
Reviewed by:
Larissa Hirsch, MD
Date reviewed: November 2007
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
© 1995-2009 The Nemours Foundation/KidsHealth. All rights reserved.