Fever in children

Though much has been written regarding fever, I find the following article from website kidshealth.org by Mary LGavin quite useful.


Every parent has probably 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 that your child has a fever, but you're unsure of what to do next. Should you get out the thermometer? Should you call the doctor?

Even if your child does have a fever, it's likely that it's not 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 your child uncomfortable and can aggravate problems such as dehydration.

But there are steps you can take to correctly take your child's temperature and make your child comfortable when it's a little higher than usual. In this article, we'll talk 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 98.6 degrees Fahrenheit, or about 37 degrees 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 by itself fever 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 can't regulate their body temperature.

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 your baby's or toddler's temperature is higher than 100 degrees Fahrenheit (37.8 degrees Celsius).


How Do I Know if My Child's Fever Is a Sign of Something Serious?

In the past, doctors advised treating a fever on the basis of temperature alone. But now, they recommend taking both the temperature and the child's overall condition into account.

Children whose temperatures are lower than 102 degrees Fahrenheit (38.9 degrees Celsius) usually 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 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, call your baby's doctor or go to the emergency department. Even a slight fever can be a sign of a potentially serious infection in very young infants.

For older children, take behavior and activity level into account. By watching how your child behaves, you can get a pretty good idea as to whether he or she has a minor illness or needs to be seen by a doctor.

The illness is probably not serious if your child:

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.

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 tell 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 a child's temperature.

By using a reliable thermometer, you can tell if your child has a fever if his or her temperature is at or higher than one of the following levels:

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 102 to 104 degrees Fahrenheit, or 38.9 to 40 degrees Celsius, range), but doesn't usually indicate a serious problem. And serious infections may cause no fever or even an abnormally low body temperature, especially in young infants.

Because fevers may rise and fall, a child with fever may experience chills, which occur when the body tries to generate additional heat when the body's temperature begins to rise. The child may sweat as the body releases extra heat when the temperature starts to drop.

Sometimes children with a fever may also breathe faster than usual and may have a higher heart rate. You should call your child's doctor if your child is having difficulty breathing, is breathing a lot faster than normal, or continues to breathe fast after the fever comes down.

What Kind of Thermometer Should I Use?

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:

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, accurate, and easy to use in older children, electronic ear thermometers aren't as accurate for very young children as digital thermometers and are more expensive. The American Academy of Pediatrics (AAP) advises against using electronic ear thermometers for infants younger than 3 months.

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 children. If you need to know your child's exact temperature, plastic strip thermometers are not the way to go.

Forehead thermometers may be a reasonable alternative to ear thermometers, if your infant is younger than a year old. But they are not as accurate as oral or rectal digital thermometers.

Pacifier thermometers may seem convenient, but again, they're unreliable 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 commonly used, but the AAP now advises against using them 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 child's doctor or your local health department about how and where to dispose of your 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 figure out if your 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, children 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 Do I Use a Digital Thermometer?

A digital thermometer offers the quickest, most accurate way to take your child's temperature and can be used in the mouth, armpit, or rectum. Before you use this device, 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 side of the thermometer). Then, 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:

  1. Lubricate the tip of the thermometer with a water-soluble lubricating jelly (talk with your pharmacist or child's doctor).
  2. Place your child face down across your lap while supporting the head, or lay the child down on a firm, flat surface, such as a changing table.
  3. Place one hand firmly on your child's lower back to hold him or her still.
  4. With your other hand, insert the lubricated thermometer through the anal opening, about half an inch to 1 inch (about 1.25 to 2.5 centimeters) into the rectum. Stop if you feel any resistance.
  5. 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.
  6. Wait until you hear the appropriate number of beeps or other signal that the temperature is ready to be read. If you'd like to keep a record, write down the temperature, noting the time of day.

To take an oral temperature: This process is easy in an older, cooperative child.

  1. 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.
  2. 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 ask him or her to relax and breathe normally through the nose.
  3. Wait until you hear the appropriate number of beeps or other signal that the temperature is ready to be read. Read and 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 your 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 if your child can't hold a thermometer in his or her mouth.

  1. Remove your child's shirt and undershirt, and place the thermometer under your child's armpit (it must be touching skin only, not clothing).
  2. Fold your child's arm across his or her chest to hold the thermometer in place.
  3. Wait until you hear the appropriate number of beeps or other signal that the temperature is ready to be read. Read and write down the number on the screen, noting the time of day that you took the reading.

Whatever method you choose, here are some additional tips to keep in mind:

How Can I Make My Child Feel Better?

Again, not all fevers need to be treated. And, in most cases, a fever should be treated only if it's causing your child discomfort. Here are some things you can do to alleviate the symptoms that often accompany a fever:

When Should I Call My Child's 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 child's doctor if you have an:

If an older child has a fever of less than 104 degrees, call the doctor if the child also:

Seek emergency care if your child shows any of the following signs along with a fever:

Also, check with 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, children 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 your child is acting 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 child's doctor for advice.

Reviewed by: Mary L. Gavin, MD
Date reviewed: October 2004

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