What's a Fever?

You come home from school feeling awful with a sore throat. Your mom takes your temperature with a thermometer. Within a few minutes, you hear the word fever.

But what are fevers, exactly? Why do kids get them? Why do parents and doctors care so much about them? Let's find out.

What Causes a Fever?

Most human beings have a body temperature of around 98.6°F (37°C). Some people will have a normal temperature that's a little higher; others will have a normal temperature that's a little lower.

Most people's body temperatures even change a little bit during the course of the day: It is usually a little lower in the morning and a little higher in the evening. For most kids, their body temperature stays pretty much the same from day to day — until germs enter the picture.

Remember that strep throat that made you feel so rotten? Or another time when the flu made you feel tired and achy? These kinds of infections are caused by germs that make their way into your body, usually in the form of bacteria (say: bak-TEER-ee-uh) or viruses.

When these germs march in and make you sick, your body's thermostat goes higher. Instead of saying your body should be 98.6°F (37°C), your body's thermostat might say that it should be 102°F (38.9°C).

Why does your body change to a new temperature? Researchers believe turning up the heat is the body's way of fighting the germs and making your body a less comfortable place for them.

A fever is also a good signal to you, your parents, and your doctor that you are sick. Without a fever, it's much harder to tell if a person has an infection. That's why grown-ups are concerned when you have a fever.

Fighting a Fever

For almost all kids, fevers aren't a big problem. When the cause of the fever is treated or goes away on its own, your body temperature comes back down to normal and you feel like your old self again. Most doctors agree that many kids with a fever don't need to take any special medicine unless their fevers are making them uncomfortable.

If a kid has a higher fever and feels uncomfortable, the doctor might tell a parent to give the child medicine. The two medicines most often recommended are acetaminophen (say: uh-SEE-tuh-min-uh-fen) or ibuprofen (say: eye-byoo-PRO-fen). The medicine blocks the chemicals that tell the body to turn up the heat. Kids should never take aspirin to treat a fever because it can cause a rare but serious illness.

If you have a fever, your mom or dad will probably ask you to drink more fluids than usual. That's important because as your body heats up, it's easy for it to get dehydrated (say: dee-HI-dray-ted). This means there isn't enough water in your body. You have a lot of choices when it comes to fluids — juice, water, sports drinks, soup, flavored gelatin, and even ice pops.

Before you know it, your mom or dad will pull the thermometer out of your mouth and say, "Your temperature is normal. No more fever!"