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:

• 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.