A fever is the body's normal and healthy reaction to infection and other illnesses, both minor and serious. Fevers help the body fight infection. A fever is a symptom, not a disease. In most cases, a fever means that your child has a minor illness. Often you must look at your child's other symptoms to find out how serious the illness is. It may be scary when your child's temperature goes up. But a fever isn't harmful.
The average normal body temperature taken orally (under the tongue) is about 98.6 F (37 C). It usually rises during the day from a low of 97.4 F (36.3 C) in the morning to a high of 99.6 F (37.6 C) in the late afternoon. Each child has a normal temperature range that may be different from another child's. Mild increases to 100.4 F (38 C) can be caused by exercising, wearing too many clothes, taking a hot bath, or being outside in hot weather.
If a low body temperature is your child's only symptom, it's not something to worry about. If a low body temperature occurs with other symptoms, such as chills, shaking, breathing problems, or confusion, then this may be a sign of more serious illness.
Low body temperature may occur from cold exposure, shock, alcohol or drug use, or certain metabolic disorders, such as diabetes or hypothyroidism. A low body temperature may also occur with an infection. This is most likely in newborns, older adults, and people who are frail. An overwhelming infection, such as sepsis, may also cause an abnormally low body temperature.
Temperature varies depending on how you take it. The most common ways to measure it are:
You can also use:
Some methods may not be as reliable or accurate as others.
If you think that your child has a fever but you can't measure his or her temperature, it's important to look for other symptoms of illness.
Children tend to run higher fevers than adults. The degree of fever may not show how serious your child's illness is. With a minor illness, such as a cold, a child may have an oral temperature of 104 F (40 C) . But a very serious infection may not cause a fever or may cause only a mild fever. With many illnesses, a fever temperature can go up and down very quickly and often. So be sure to look for other symptoms along with the fever.
Babies with a fever often have an infection caused by a virus, such as a cold or the flu. Infections caused by bacteria, such as a urinary infection or bacterial pneumonia, also can cause a fever. Babies younger than 3 months should be seen by a doctor anytime they have a fever. That's because they can get extremely sick quickly.
A fever in a healthy child usually isn't dangerous, especially if the child doesn't have other symptoms and the fever goes away in 3 to 4 days. Most children who have a fever will be fussy and play less. And they may not eat as much as usual.
High fevers may make your child uncomfortable, but they rarely cause serious problems. There is no medical evidence that fevers from infection cause brain damage. The body limits a fever caused by infection from rising above 106 F (41.1 C) orally. But outside heat—such as from being in a car that is parked in the sun—can cause body temperature to rise above 107 F (41.7 C) . In those cases, brain damage can occur.
Childhood immunizations can reduce the risk for fever-related illnesses, such as Haemophilus influenzae type b (Hib) infection. No vaccine is 100% effective. But most routine childhood immunizations are effective for 85% to 95% of the children who get them.
It's not unusual for a preschool-aged child to have 7 to 10 viral infections in a year. Each new viral infection may cause a fever. It may seem that a fever is ongoing. But if 48 hours pass between fevers, then the new fever is most likely from a new illness.
Common causes of a fever include:
Teething may cause a mild increase in your child's temperature. But if the temperature is higher than 100.4 F (38 C) orally, look for symptoms that may be related to an infection or illness.
A fever that rises quickly may lead to a fever seizure in some children. After a fever has reached a high temperature, the risk of a seizure is less. Fever seizures can be scary to see. But they usually don't cause other problems, such as brain damage, intellectual disability, or learning problems.
It can be hard to know if you should call your doctor when your child (age 1 to 11 years) has a fever, especially during the cold and flu season. The degree of the fever may not be related to the seriousness of the illness. The way your child looks and acts is a better guide than the thermometer. Most children will be less active when they have a fever.
If your child is comfortable and alert, is eating well, is drinking enough fluids, is urinating normal amounts, and seems to be improving, home treatment without medicine is all that's needed for a fever. Dress your child lightly. Don't wrap him or her in blankets. Dressing lightly will help your child's body cool down.
Try these home treatment measures to make sure that your child is drinking enough fluids and doesn't get dehydrated while he or she has a fever.
Call 911 anytime you think your child may need emergency care. For example, call if:
Call your doctor now or seek immediate medical care if:
Watch closely for changes in your child's health, and be sure to contact your doctor if:
Need treatment fast? We have more than a dozen Parkview walk-in clinics in northeast Indiana and northwest Ohio.