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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.
Normal body temperature
The average normal body temperature is about 98.6 °F (37°C), measured orally (under the tongue). It usually rises during the day from a lower temperature in the morning to a higher temperature in the late afternoon. Each child has a normal temperature range that may be different from another child's. Mild increases in temperature can be caused by exercising, wearing too many clothes, taking a hot bath, or being outside in hot weather.
Fever
Temperature measurements vary depending on how you take it. The most common ways to measure it are:
Under the tongue.
In the armpit.
In the rectum.
In the ear.
You can also use:
Forehead thermometers.
Pacifier thermometers.
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 their temperature, it's important to look for other symptoms of illness.
Children tend to have 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, your child may have a fever. But a very serious infection may cause little or no 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. 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.
Causes of fever
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:
Viral infections, such as colds, flu, and chickenpox.
Bacterial infections, such as a urinary tract infection.
Immunizations.
Teething may cause a mild increase in your child's temperature. But if the temperature gets high, 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.
Low body temperature
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, or certain metabolic disorders, such as diabetes. 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.
Check Your Symptoms
Do you think your child may have a fever or chills?
Yes
Fever or chills
No
Fever or chills
How old are you?
Less than 3 months
Less than 3 months
3 months to 3 years
3 months to 3 years
4 to 6 years
4 to 6 years
7 to 11 years
7 to 11 years
12 years or older
12 years or older
Are you male or female?
Male
Male
Female
Female
The medical assessment of symptoms is based on the body parts you have.
If you are transgender or nonbinary, choose the sex that matches the body parts (such as ovaries, testes, prostate, breasts, penis, or vagina) you now have in the area where you are having symptoms.
If your symptoms aren’t related to those organs, you can choose the gender you identify with.
If you have some organs of both sexes, you may need to go through this triage tool twice (once as "male" and once as "female"). This will make sure that the tool asks the right questions for you.
Has your child had a fever seizure?
Fever seizures are uncontrolled muscle spasms that can happen when a child's body temperature goes up quickly.
Taking a rectal temperature is the only way to be sure that a baby this age does not have a fever. If you don't know the rectal temperature, it's safest to assume the baby has a fever and needs to be seen by a doctor. Any problem that causes a fever at this age could be serious.
Does your child have shaking chills or very heavy sweating?
Shaking chills are a severe, intense form of shivering. Heavy sweating means that sweat is pouring off the child or soaking through his or her clothes.
NOTE: Most people have an average body temperature of about 98.6°F (37°C). But it can vary by a degree or more and still be considered normal. If a low body temperature is your only symptom, it’s usually not something to worry about. But be sure to watch for other symptoms.
High: 104°F (40°C) or higher, oral
High fever: 104°F (40°C) or higher, oral
Moderate: 100.4°F (38°C) to 103.9°F (39.9°C), oral
Moderate fever: 100.4°F (38°C) to 103.9°F (39.9°C), oral
Do you think that a medicine or a vaccine may be causing the fever?
Think about whether the fever started soon after you began using a new medicine or a higher dose of a medicine. Or did it start after you got a shot or vaccine?
Yes
Medicine or vaccine may be causing the fever
No
Medicine or vaccine may be causing the fever
Many things can affect how your body responds to a symptom and what kind of care you may need. These include:
Your age. Babies and older adults tend to get sicker quicker.
Your overall health. If you have a condition such as diabetes, HIV, cancer, or heart disease, you may need to pay closer attention to certain symptoms and seek care sooner.
Medicines you take. Certain medicines, such as blood thinners (anticoagulants), medicines that suppress the immune system like steroids or chemotherapy, herbal remedies, or supplements can cause symptoms or make them worse.
Recent health events, such as surgery or injury. These kinds of events can cause symptoms afterwards or make them more serious.
Your health habits and lifestyle, such as eating and exercise habits, smoking, alcohol or drug use, sexual history, and travel.
Try Home Treatment
You have answered all the questions. Based on your answers, you may be able to take care of this problem at home.
Try home treatment to relieve the symptoms.
Call your doctor if symptoms get worse or you have any concerns (for example, if symptoms are not getting better as you would expect). You may need care sooner.
Babies can quickly get dehydrated when they lose fluids because of problems like vomiting or fever.
Symptoms of dehydration can range from mild to severe. For example:
The baby may be fussy or cranky (mild dehydration), or the baby may be very sleepy and hard to wake up (severe dehydration).
The baby may have a little less urine than usual (mild dehydration), or the baby may not be urinating at all (severe dehydration).
You can get dehydrated when you lose a lot of fluids because of problems like vomiting or fever.
Symptoms of dehydration can range from mild to severe. For example:
You may feel tired and edgy (mild dehydration), or you may feel weak, not alert, and not able to think clearly (severe dehydration).
You may pass less urine than usual (mild dehydration), or you may not be passing urine at all (severe dehydration).
Severe dehydration means:
The baby may be very sleepy and hard to wake up.
The baby may have a very dry mouth and very dry eyes (no tears).
The baby may have no wet diapers in 12 or more hours.
Moderate dehydration means:
The baby may have no wet diapers in 6 hours.
The baby may have a dry mouth and dry eyes (fewer tears than usual).
Mild dehydration means:
The baby may pass a little less urine than usual.
Symptoms of difficulty breathing can range from mild to severe. For example:
You may feel a little out of breath but still be able to talk (mild difficulty breathing), or you may be so out of breath that you cannot talk at all (severe difficulty breathing).
It may be getting hard to breathe with activity (mild difficulty breathing), or you may have to work very hard to breathe even when you’re at rest (severe difficulty breathing).
Symptoms of difficulty breathing in a baby or young child can range from mild to severe. For example:
The child may be breathing a little faster than usual (mild difficulty breathing), or the child may be having so much trouble that the nostrils are flaring and the belly is moving in and out with every breath (severe difficulty breathing).
The child may seem a little out of breath but is still able to eat or talk (mild difficulty breathing), or the child may be breathing so hard that he or she cannot eat or talk (severe difficulty breathing).
Sudden drooling and trouble swallowing can be signs of a serious problem called epiglottitis. This problem can happen at any age.
The epiglottis is a flap of tissue at the back of the throat that you can't see when you look in the mouth. When you swallow, it closes to keep food and fluids out of the tube (trachea) that leads to the lungs. If the epiglottis becomes inflamed or infected, it can swell and quickly block the airway. This makes it very hard to breathe.
The symptoms start suddenly. A person with epiglottitis is likely to seem very sick, have a fever, drool, and have trouble breathing, swallowing, and making sounds. In the case of a child, you may notice the child trying to sit up and lean forward with his or her jaw forward, because it's easier to breathe in this position.
Many prescription and nonprescription medicines can trigger an allergic reaction and cause a fever. A few examples are:
Antibiotics.
Barbiturates, such as phenobarbital.
Aspirin, if you take too much.
Fever can be a symptom of almost any type of infection. Symptoms of a more serious infection may include the following:
Skin infection: Pain, redness, or pus
Joint infection: Severe pain, redness, or warmth in or around a joint
Bladder infection: Burning when you urinate, and a frequent need to urinate without being able to pass much urine
Kidney infection: Pain in the flank, which is either side of the back just below the rib cage
Abdominal infection: Belly pain
Symptoms of heatstroke may include:
Feeling or acting very confused, restless, or anxious.
Trouble breathing.
Sweating heavily, or not sweating at all (sweating may have stopped).
Skin that is red, hot, and dry, even in the armpits.
Passing out.
Seizure.
Nausea and vomiting.
Heatstroke occurs when the body can't control its own temperature and body temperature continues to rise.
Severe dehydration means:
The child's mouth and eyes may be extremely dry.
The child may pass little or no urine for 12 or more hours.
The child may not seem alert or able to think clearly.
The child may be too weak or dizzy to stand.
The child may pass out.
Moderate dehydration means:
The child may be a lot more thirsty than usual.
The child's mouth and eyes may be drier than usual.
The child may pass little or no urine for 8 or more hours.
The child may feel dizzy when he or she stands or sits up.
Mild dehydration means:
The child may be more thirsty than usual.
The child may pass less urine than usual.
Certain health conditions and medicines weaken the immune system's ability to fight off infection and illness. Some examples in children are:
Diseases such as diabetes, cystic fibrosis, sickle cell disease, and congenital heart disease.
Steroid medicines, which are used to treat a variety of conditions.
Medicines taken after organ transplant.
Chemotherapy and radiation therapy for cancer.
Not having a spleen.
Temperature varies a little depending on how you measure it. For children up to 11 years old, here are the ranges for high, moderate, and mild according to how you took the temperature.
Oral (by mouth), ear, or rectal temperature
High: 104° F (40° C) and higher
Moderate: 100.4° F (38° C) to 103.9° F (39.9° C)
Mild: 100.3° F (37.9° C) and lower
A forehead (temporal) scanner is usually 0.5° F (0.3° C) to 1° F (0.6° C) lower than an oral temperature.
Armpit (axillary) temperature
High: 103° F (39.5° C) and higher
Moderate: 99.4° F (37.4° C) to 102.9° F (39.4° C)
Mild: 99.3° F (37.3° C) and lower
Note: For children under 5 years old, rectal temperatures are the most accurate.
Sudden tiny red or purple spots or sudden bruising may be early symptoms of a serious illness or bleeding problem. There are two types.
Petechiae (say "puh-TEE-kee-eye"):
Are tiny, flat red or purple spots in the skin or the lining of the mouth.
Do not turn white when you press on them.
Range from the size of a pinpoint to the size of a small pea and do not itch or cause pain.
May spread over a large area of the body within a few hours.
Are different than tiny, flat red spots or birthmarks that are present all the time.
Purpura (say "PURR-pyuh-ruh" or “PURR-puh-ruh”):
Is sudden, severe bruising that occurs for no clear reason.
May be in one area or all over.
Is different than the bruising that happens after you bump into something.
You can use a small rubber bulb (called an aspirating bulb) to remove mucus from your baby's nose or mouth when a cold or allergies make it hard for the baby to eat, sleep, or breathe.
To use the bulb:
Put a few saline nose drops in each side of the baby's nose before you start.
Position the baby with his or her head tilted slightly back.
Squeeze the round base of the bulb.
Gently insert the tip of the bulb tightly inside the baby's nose.
Release the bulb to remove (suction) mucus from the nose.
Don't do this more than 5 or 6 times a day. Doing it too often can make the congestion worse and can also cause the lining of the nose to swell or bleed.
Severe trouble breathing means:
The child cannot eat or talk because he or she is breathing so hard.
The child's nostrils are flaring and the belly is moving in and out with every breath.
The child seems to be tiring out.
The child seems very sleepy or confused.
Moderate trouble breathing means:
The child is breathing a lot faster than usual.
The child has to take breaks from eating or talking to breathe.
The nostrils flare or the belly moves in and out at times when the child breathes.
Mild trouble breathing means:
The child is breathing a little faster than usual.
The child seems a little out of breath but can still eat or talk.
Shock is a life-threatening condition that may occur quickly after a sudden illness or injury.
Babies and young children often have several symptoms of shock. These include:
Passing out (losing consciousness).
Being very sleepy or hard to wake up.
Not responding when being touched or talked to.
Breathing much faster than usual.
Acting confused. The child may not know where he or she is.
If you're not sure if a child's fever is high, moderate, or mild, think about these issues:
With a high fever:
The child feels very hot.
It is likely one of the highest fevers the child has ever had.
With a moderate fever:
The child feels warm or hot.
You are sure the child has a fever.
With a mild fever:
The child may feel a little warm.
You think the child might have a fever, but you're not sure.
A baby that is extremely sick:
May be limp and floppy like a rag doll.
May not respond at all to being held, touched, or talked to.
May be hard to wake up.
A baby that is sick (but not extremely sick):
May be sleepier than usual.
May not eat or drink as much as usual.
Pain in children under 3 years
It can be hard to tell how much pain a baby or toddler is in.
Severe pain (8 to 10): The pain is so bad that the baby cannot sleep, cannot get comfortable, and cries constantly no matter what you do. The baby may kick, make fists, or grimace.
Moderate pain (5 to 7): The baby is very fussy, clings to you a lot, and may have trouble sleeping but responds when you try to comfort him or her.
Mild pain (1 to 4): The baby is a little fussy and clings to you a little but responds when you try to comfort him or her.
Pain in children 3 years and older
Severe pain (8 to 10): The pain is so bad that the child can't stand it for more than a few hours, can't sleep, and can't do anything else except focus on the pain. No one can tolerate severe pain for more than a few hours.
Moderate pain (5 to 7): The pain is bad enough to disrupt the child's normal activities and sleep, but the child can tolerate it for hours or days.
Mild pain (1 to 4): The child notices and may complain of the pain, but it is not bad enough to disrupt his or her sleep or activities.
Symptoms of serious illness in a baby may include the following:
The baby is limp and floppy like a rag doll.
The baby doesn't respond at all to being held, touched, or talked to.
The baby is hard to wake up.
Symptoms of serious illness may include:
A severe headache.
A stiff neck.
Mental changes, such as feeling confused or much less alert.
Extreme fatigue (to the point where it's hard for you to function).
Shaking chills.
Seek Care Now
Based on your answers, you may need care right away. The problem is likely to get worse without medical care.
Call your doctor now to discuss the symptoms and arrange for care.
If you cannot reach your doctor or you don't have one, seek care in the next hour.
You do not need to call an ambulance unless:
You cannot travel safely either by driving yourself or by having someone else drive you.
You are in an area where heavy traffic or other problems may slow you down.
Call 911 Now
Based on your answers, you need emergency care.
Call 911 or other emergency services now.
Sometimes people don't want to call 911. They may think that their symptoms aren't serious or that they can just get someone else to drive them. Or they might be concerned about the cost. But based on your answers, the safest and quickest way for you to get the care you need is to call 911 for medical transport to the hospital.
Seek Care Today
Based on your answers, you may need care soon. The problem probably will not get better without medical care.
Call your doctor today to discuss the symptoms and arrange for care.
If you cannot reach your doctor or you don't have one, seek care today.
If it is evening, watch the symptoms and seek care in the morning.
It can be hard to know if you should call your doctor when your newborn or baby younger than 1 year of age 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 baby looks and acts is a better guide than the thermometer. Most babies will be less active when they have a fever.
If your baby 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 baby in lightweight clothes to help them stay cool. Don't wrap your baby in blankets.
Try these home treatment measures to make sure that your baby is drinking enough fluids and doesn't get dehydrated while they have a fever.
Don't let your baby get dehydrated.
If you breastfeed your baby, nurse them more often. Offer each breast to your baby for 1 to 2 minutes every 10 minutes.
If you use a bottle to feed your baby, increase the number of feedings to make up for lost fluids. The amount of extra fluid your baby needs depends on your baby's age and size. For example, a newborn may need as little as 1 fl oz (30 mL) at each extra feeding. A 12-month-old baby may need as much as 3 fl oz (90 mL) at each extra feeding.
Ask your doctor if you need to use an oral rehydration solution (ORS) if your baby still isn't getting enough fluids from formula or the breast. The amount of ORS your baby needs depends on your baby's age and size. You can give the ORS in a dropper, spoon, or bottle.
If your baby has started eating cereal, you may replace lost fluids with cereal. You also may feed your baby strained bananas and mashed potatoes if your baby has had these foods before.
Keep your baby comfortable. Lowering your baby's temperature is important when the fever is causing discomfort. If your baby is uncomfortable:
Try giving your baby a sponge bath with lukewarm water. Don't use cold water, ice, or rubbing alcohol.
Encourage quiet activities.
Watch for signs of dehydration. These signs include your baby having fewer or no wet diapers and a dry mouth and dry eyes (fewer tears than usual).
Caring for a child
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 in lightweight clothes to help them stay cool. Don't wrap them in blankets.
Try these home treatment measures to make sure that your child is drinking enough fluids and doesn't get dehydrated while they have a fever.
Don't let your child get dehydrated.
Make sure that your child drinks often. Frequent, small amounts work best.
Allow your child to drink as much fluid as they want. Encourage your child to drink extra fluids or suck on flavored ice pops. Don't give your child fruit juice or soda pop. They contain too much sugar and not enough of the essential minerals (electrolytes) that are being lost. Diet soda pop lacks calories that your child needs.
Cereal mixed with milk or water may also be used to replace lost fluids.
If your child still isn't getting enough fluids, you can try an oral rehydration solution (ORS).
Keep your child comfortable. Lowering your child's temperature is important when the fever is causing discomfort. If your child is uncomfortable:
Try giving your child a sponge bath with lukewarm water. Don't use cold water, ice, or rubbing alcohol.
Encourage quiet activities.
Watch for signs of dehydration. These include your child being thirstier than usual and having less urine than usual.
When to call for help during self-care
Call a doctor if any of the following occur during self-care at home:
Decreased alertness.
New or worse dehydration, such as being thirsty or urinating less.
Author: Ignite Healthwise, LLC Staff Clinical Review Board All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Clinical Review Board All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
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