There is almost nothing as stressful as dealing with a sick or feverish child. It’s a parental instinct to worry and, sometimes, assume the worst. But the fact is, most kids get fevers from time to time throughout childhood, and not all are causes for alarm. “A fever is not always a bad thing because it shows your child’s body is fighting an infection,” says Preeti Parikh, MD, a New York City pediatrician, and Executive Medical Director at GoodRx. Still, it’s useful to understand when a fever warrants a call to your pediatrician and when a fever is something you can manage at home. Let’s take a look at the basics of fevers in children, what the warning signs are for a fever that’s turning dangerous, and when it makes sense to call your pediatrician.

How Do I Know When My Child Has a Fever?

Other than simply being warm to the touch, there are several warning signs that your child might have or be developing a fever, says Molly O’Shea, MD, a pediatrician at Birmingham Pediatrics Wellness Center in Michigan. “Signs include sleeping more than usual or at unusual times, being less energetic than usual, or not eating and drinking as they normally would,” Dr. O’Shea explains. “Older children may complain of headache, sore eyes, or body aches when their temperature is high.” But your child may display different symptoms with their fever, depending on what’s causing the high temperature. While some children seem tired or “off” with a fever, yours might be bouncing off the walls! Fevers in children have several different causes, including infections and illnesses, side effects from vaccinations, and even overdressing, especially in young children. If your child’s fever is caused by a virus or other infection, they will usually also have symptoms of that illness. For example, says Dr. Parikh, your child may have a sore throat, cold symptoms, or diarrhea and vomiting along with their fever. Other signs of a fever include experiencing chills, and then feeling overheated, says Dr. Parikh. Your child may also have a higher breathing rate and higher heart rate, she adds.

What Temperature Is Considered a Fever?

The only way you can know for sure if your child has a fever is by taking their temperature with a thermometer. When taking your child’s temperature, the Academy of American Pediatrics (AAP) highly recommends using a digital thermometer over a glass thermometer. There are several different types of digital thermometers out there, including multi-use digital thermometers, temporal artery (forehead) thermometers, and tympanic​ (ear) thermometers. The type of thermometer you use to measure your child’s temperature will vary based on their age. For babies under three months of age, the most accurate way to take a temperature is through the rectum. Dr. Parikh doesn’t recommend using ear thermometers on any babies younger than 6 months old and says that you should wait to take your child’s temperature orally until they are at least 4 years old. However you take your child’s temperature, any reading over 100.4 degrees (Fahrenheit) is considered a fever. “No matter how you measure the temperature, you have to measure 100.4 before it counts,” says Dr. O’Shea. “Even if your child usually runs low, 100.4 is still the cutoff.”

When Does a Fever Become Dangerous?

It’s common to feel scared when your child spikes a fever, but thankfully, there are only a few specific situations when a fever is dangerous to your child. In terms of temperature, a fever has to get fairly high before it becomes dangerous. This will vary based on your child’s age, says Dr. Parikh. “A fever becomes dangerous if your child has a temperature of 100.4 rectally under the age of three months,” she explains. Any fever over 104 can be dangerous, no matter your child’s age, she adds. But it’s not just the reading on the thermometer that you should be concerned about, Dr. Parikh points out. “It is very important to not just look at the number, but how your child looks,” Dr. Parikh says. “For example, if they are very irritable, out of it, breathing very fast, having difficulty breathing, dehydrated, having a seizure, or a stiff neck, it could be a sign of an emergency.”

When Should I Call My Child’s Healthcare Provider About a Fever?

Above all, it’s important to understand that it is never “wrong” to call your pediatrician if you are concerned about your child, assures Dr. O’Shea. “Whenever your parental ‘spidey sense’ is telling you to contact your child’s healthcare provider, you should,” she offers. “It is better to be safe and reassured!” That being said, there are certain instances in which you clearly should contact your pediatrician for your child’s fever. Let’s take a look at what these instances are.

Your Child Is Acting Strangely

You know your child best, and if they are not acting like themselves or just seem “off,” you should not hesitate to contact your pediatrician. So, if your child is unusually fussy, listless, can’t be woken, or just seems very uncomfortable, you should reach out to your doctor.

Your Child is Dehydrated

You should also contact your healthcare provider if your child isn’t able to keep down fluids and is showing signs of dehydration. Your child may be dehydrated if they are going through fewer diapers than usual or making fewer trips to the bathroom to urinate.

Your Child Is Under 3 Months Old

Fever in older children can often be managed at home, but any fever in a young baby is a reason for a prompt call to your doctor. Your call should be even more urgent if your baby has an underlying medical condition. “If you have a baby that is under three months of age with a rectal temperature of 100.4 F or has an underlying health condition such as sickle cell, then you should call your pediatrician,” says Dr. Parikh. Other underlying conditions that put your feverish baby at greater risk include cancer, immune system conditions, and a history of taking steroid medications.

Your Child’s Fever Is Not Coming Down With Medication

Another reason to call your pediatrician is if your child’s fever is not coming down with doctor-approved fever reducers like acetaminophen or ibuprofen. “If your child is very uncomfortable or listless and, despite using a pain reliever, is not perking up in an hour, you should contact your healthcare provider,” Dr. O’Shea says.

Your Child’s Fever Is Lasting Several Days

If your child’s fever hasn’t cleared up after about five days, you should check in with your child’s pediatrician to rule out any underlying conditions that might be causing the fever to last so long or to rule out any complications from an illness. Additionally, says Dr. Parikh, you should consider contacting your pediatrician if your child has had a fever lasting over 24 hours, but no other symptoms. “The parent should talk to the doctor because it could be something like a urinary tract infection in a baby who can’t talk,” she explains.

Your Child Has Had a Febrile Seizure

Sometimes a child will have a seizure while they have a fever, especially if their temperature rises rapidly. These febrile seizures can be really unsettling for a parent to witness. They usually only last a few minutes. Symptoms include twitching, jerky movements, rolled eyes, moaning, and passing out. You should know that febrile seizures are quite common, and usually don’t suggest that your child has developed a chronic neurologic disease. That said, if your child has one, you should follow up with their healthcare provider to rule out anything more serious.

Tips for Monitoring Your Child’s Fever

Along with reaching out to a doctor if you’re concerned, Dr. Parikh’s top tips for monitoring a fever include taking note of your child’s temperature before trying to bring it down with medications. This way you can monitor the curve of your child’s fever and watch for changes. She also urges parents to use the correct thermometer for their child’s age and to use it on the right part of their child’s body. Otherwise, you may not get an accurate temperature reading, she warns. As for fever treatment, Dr. O’Shea says that methods like lukewarm baths and fever reducers acetaminophen or ibuprofen can be useful. However, she says that certain methods are best avoided. “Alcohol wipe-downs and cool baths are dangerous and should not be used to lower fevers,” she advises.

A Word from Verywell

It’s our job as parents to keep our children safe and well, so it makes sense that we’d experience stress and even panic when our children become feverish. While it’s true that your child will get many fevers and most will not warrant a call to your pediatrician, there are certain instances where a call will be necessary—including if your child is listless, non-responsive, is under 3 months, or has a fever higher than 104 at any age. Either way, it’s always better to be safe than sorry when it comes to your child’s health, and so there’s rarely a reason why you shouldn’t contact your pediatrician. Not only that, but your pediatrician expects calls from anxious parents. “Your pediatrician is there for you, so if you don’t feel comfortable with how your child looks it is best to always call them to check-in,” says Dr. Parikh. “That is what we are here for.”