Having a fever makes you feel like your body is cooking from within. Being feverish leaves you lethargic, sometimes mixing the high body temperature with uncomfortable chills. And in the era of COVID-19 fever can take on a new meaning.
If you’re a parent, it’s tempting to panic when your child spikes a high temperature. However, in and of itself, a fever is usually harmless. A temperature rise is often the body’s first response to common viral or bacterial illnesses and serves as a warning sign that you’re getting sick.
Below, an urgent care expert and a pediatrician explain when you should seek medical advice for a fever, or when to manage at home with over-the-counter products and simple-but-effective comfort measures.
What Constitutes a Fever?
To cope with a fever at home, it helps to understand what your body’s internal temperature ranges mean.
“A fever, which is an increase in body temperature, is actually one of our body’s natural defenses against outside attacks like infections,” says pediatrician Dr. Shelly Vaziri Flais, an American Academy of Pediatrics spokesperson and a partner with Pediatric Health Associates based in Naperville, Illinois.
There’s no single number that constitutes a normal temperature – it’s really a range. Thresholds for concern over fever also depend on whether it’s an infant, teen, young or older adult experiencing the fever.
A normal temperature runs anywhere from about 97 degrees to about 100 degrees Fahrenheit, Flais says. As a primary care pediatrician, she tells parents that upper 99s can be within the normal range for a child depending on the child’s age, general health and what they’re doing at the time. For instance, a kid’s temperature could slightly rise when they exercise, take a hot bath or wear clothes that are too warm.
A temperature above 100.4 F (or 38 degrees Celsius) is considered a fever for everyone, Flais says.
When you’re older, your day-to-day temperature may be lower than it used to be. It’s good to have a sense of what your normal temperature is, so you know when it’s abnormal for you.
“As we get older, our metabolism (somewhat) declines and our base core temperature — our body temperature as it normally is — may actually be a little lower than typical,” says Dr. Devin Minior, chief medical officer for Banner Urgent Care, part of Arizona-based Banner Health. “And so, when individuals develop a fever, they’re off their baseline by a couple degrees. And even though they’re under that 100.4 degrees Fahrenheit, or 38 degrees Celsius, they may have a fever.”
Managing a Fever at Home
Having the appropriate thermometer, familiar over-the-counter drugs and basic comfort supplies allow you to track and stay on top of a fever and its related symptoms, or just feel a bit better while waiting a fever out.
Electronic thermometers provide rapid results and have essentially replaced mercury thermometers as the standard. These are thermometer types for at-home use:
— Rectal (digital). For infants and toddlers, taking a temperature rectally (in the bottom) is considered the most accurate method.
— Oral (digital). Taking a temperature by mouth is best for children who can cooperate.
— Underarm/axillary (digital). Although less invasive, axillary temps are also less accurate. Armpit temperatures can be good for screening in infants, but if the temperature reading is elevated, then parents should recheck with a rectal temp.
— Ear (tympanic membrane). Ear probes work by measuring heat waves in the eardrum. They can give parents an early sense of whether a child is feverish, although earwax or certain ear canal shapes may affect accuracy.
— Forehead (temporal artery). The noninvasive format is a plus, but forehead readings aren’t as accurate as rectal or oral temps. For COVID-19-screening purposes in public places, forehead scanners are practical as part of a comprehensive evaluation.
To monitor fever at home, oral thermometers work best, but rectal thermometers are preferred for infants and toddlers.
“For younger children, especially before their first birthday — definitely for infants — as pediatricians, we recommend a digital rectal thermometer,” Flais says. “They’re easy to read — you just turn them on and get an instant readout.”
When using a rectal thermometer, the key is to lubricate it with Vaseline or a similar product and carefully place it in the baby’s rectum, Flais explains. “The easiest way is to have them up on the changing table. And then you lift up the knees, as if you’re changing a poopy diaper, and then you just insert it a couple centimeters within and then click the button and then you get a pretty quick digital read that way because that gives you the core body temperature. We’ve had so many misreads from either forehead scanners or ear probes.”
For preschool and older kids (as well as adults) oral temperature-taking works well. “The child should be able to hold a digital thermometer under their tongue for the required amount of time,” Flais says. The thermometer will beep with the reading in about 10 seconds.
For families with several children, consider having separate thermometers for oral versus rectal temperature-taking to avoid cross-contamination, Flais advises. For instance, you can find several easy-to-differentiate kids’ thermometers with fun cartoon characters. An inexpensive digital thermometer that costs under $10 can monitor a fever just as well as expensive models with bells and whistles, she says.
OTC Fever Relievers
Doctors most commonly recommend acetaminophen and ibuprofen as over-the-counter fever-lowering medications:
— Acetaminophen (Tylenol). Acetaminophen has analgesic (pain-relieving) and antipyretic (fever-reducing) effects. It works by affecting the brain’s heat-regulating center.
— Ibuprofen (Advil or Motrin). Ibuprofen is a nonsteroidal anti-inflammatory drug. NSAIDS reduce inflammation, pain and fever. “Patients generally need to be six months or older to take ibuprofen,” Minior says. “Acetaminophen can be taken at any age.”
Other OTC drugs also reduce fever:
— Naproxen (Naprosyn, Aleve). Naproxen, a NSAID often used to treat pain from arthritic conditions like gout, can lower temperature as well.
— Aspirin. Aspirin, another NSAID, is also a salicylate drug. Salicylates have been linked to Reye’s syndrome, a rare but potentially life-threatening condition that can affect children and adolescents. Therefore, aspirin is generally not recommended for pediatric patients, Minior says. Aspirin is not recommended for treating fever under the age of 18.
In some scenarios, you can alternate acetaminophen and ibuprofen, if taking just one or the other isn’t keeping your fever down. “They work by different mechanisms,” Minior explains. “So there are a few options there.”
Because each medication is usually taken every six hours, Minior says, “you can actually flip back and forth between them every three hours.” For instance, you would start with acetaminophen at 8 a.m., take ibuprofen at 11 a.m., then another dose of acetaminophen at 2 p.m. “Going back and forth like that is absolutely reasonable.”
However, whichever medication you take for fever, it’s important to follow dosage guidelines on the label, unless otherwise prescribed.
Sometimes people aren’t aware that medications have maximum dosages or believe it’s OK to double up on medications if a fever is not well-controlled — but that isn’t true, Minior says. “You want to follow the directions on the back of your acetaminophen or ibuprofen (bottle), unless your doctor writes a specific dosage for you,” he emphasizes. Bottom line: “You can overdose on both of those medications, and you want to be really cautious about that.”
Children and Fever
For kids, “the biggest reasons we would treat a fever, either with acetaminophen or ibuprofen, is to help the child feel more comfortable, so they can get the rest they need and keep drinking fluids to stay hydrated,” Flais says.
Watching and waiting with supportive care is sometimes all that’s needed. “For older kiddos, even if they’re 101, if they’re comfortable, drinking and sleeping, you don’t have to treat the fever,” Flais says. Many medical professionals believe that a higher body temperature actually stimulates the immune system, she notes. “So, the number — in and of itself — isn’t dangerous.”
That said, it can be scary for parents when a child develops a fever. “Fever phobia” can kick in, Flais says, “especially at 2 in the morning, and you feel that it’s only going to keep rising unless you take action. But that is actually not the case — it will fluctuate back down.”
Fever and Chills
Chills sometimes go along with fever, adding to the discomfort. “That’s how the body builds up its temperature, by that actual muscle movement,” Flais says. “So, a child will subjectively feel cold. To me, that’s a clue that their body temperature is still rising and we’ve got an evolving situation.”
Other accompanying symptoms can also arise. “Heart rate can be up in a fever,” Flais says. “Breathing rate can be up in a fever.” It usually takes 30 to 45 minutes for fever-relieving medicine to settle in, she notes. “So, let’s reassess once it has brought the temperature down, because more often than not, that takes care of the issue.” However, if heart and breathing rates are still elevated after reducing the body temperature, she adds, “that merits further investigation.”
Although parents may fear that their child’s high fever could lead to a seizure, that’s actually quite uncommon.
“About 1% of children, on average, six months to six years of age, have a tendency with a rapid rise in body temperature to have a seizure,” Flais says. “If it falls under the category of a simple febrile seizure, the first time you want to get checked out by your pediatrician. But generally speaking, this still does not cause harm to the child or require further neurologic evaluation.”
When seizure-prone children come down with a simple viral infection, Flais advises parents to stay on top of it, keep them comfortable and watch and see how they’re doing. Fortunately, she adds, “usually by kindergarten or first grade, kids have outgrown this tendency.”
With older adults, a persistent temperature above their baseline should be addressed. An abnormally low temperature can also be a concern.
“Sometimes older adults may get really sick and develop a phenomenon where they actually get a low temperature, or become hypothermic, when they get sick or infected,” Minior says. “That can also be a red flag that there may be an infection going on or they may potentially be septic.” Sepsis is an overwhelming, systemic response to infection that can cause organ damage and be life-threatening.
If a typical temperature for an older individual is 98.6 degrees Fahrenheit, but their current temperature is getting down to 96 or 95, along with other symptoms, that would be concerning, Minior says. It could signal any type of infection, such as a urinary tract infection.
“Maybe somebody’s developing the flu, or somebody may have another viral illness from someone in the community who gets sick,” Minior says. “Certainly, as we get older we can develop a pneumonia in our lungs, or a skin infection.” For older adults, temperature changes can go either way with infection: “They may become hypothermic or develop a fever.”
An older adult who isn’t feeling well, doesn’t look well or isn’t behaving as usual should be evaluated for a temperature that’s even slightly higher or lower than their baseline.
Comfort and Support
For moderate fevers, these comfort and support measures can safely lower body temperature or at least help you or your child feel better:
— Hydration. With fever, It’s OK to miss a few meals if you’re not hungry, but you have to keep drinking. Fluid, not food, is what’s most important. “Staying well-hydrated is the critical component — so drinking plenty of fluids,” Minior says. However, “you don’t want to drink just pure water. You typically want to dilute that down with some type of juice or some electrolyte solution, just to make sure you’re getting appropriate electrolytes in the body.” Your body can lose essential electrolytes such as sodium, chloride and potassium when you’re sick and sweating off a fever.
— Applying cool water. “A cool bath or even a cool compress on the forehead or in the armpits absolutely can work,” Minior says. “A little bit of moisture on the body and allowing that to evaporate will help cool it.”
— Rest. Getting plenty of rest alleviates fever-related fatigue and reduces stress on the body.
— Clothing and covering. Wearing lightweight, breathable clothing is most comfortable during a fever. Covering up with light sheets or blankets helps. And for babies, cuddling them in a blanket will do the trick.
Some DIY methods for treating fever don’t really work and can add to discomfort:
— Ice baths aren’t proven to provide fever relief. In fact, rather than simply cooling a temperature, a freezing bath may drop it too much and the person becomes hypothermic — meaning they have a dangerously low body temperature, Minior warns.
— Using rubbing alcohol on the body is ineffective for cooling the skin, because the alcohol evaporates really quickly, Minor explains.
— Hand sanitizer isn’t a fever reliever. “In this day and age where we use hand sanitizer, you may notice that when you put it on your hands, your hands feel a little cold afterward,” he says. “And people may do that on the rest of their body to try and cool it down. Unfortunately, there are chemicals that can be absorbed through the skin, so if you put a lot of it on your body, it can have a negative effect on an individual.”
When to Call a Doctor
For infants under three months old, a fever is considered a medical emergency until determined otherwise, Flais says. “That needs to be checked out, because with a newborn it’s hard to tell if it’s just an upper respiratory infection or something more ominous like meningitis.”
If your infant has a fever, call your pediatrician immediately. At any age, certain symptoms occurring with fever must be addressed right away:
— Severe headache.
— Stiff neck.
— Light sensitivity.
— Shortness of breath.
You should also seek medical care for ongoing symptoms:
— Persistent vomiting and diarrhea.
— Dehydration signs: peeing less and tearless crying in infants and young children, reduced alertness and activity.
— Fever lasting beyond four or five days.
People who are immunocompromised, or who have chronic medical conditions such as sickle cell disease, cancer or heart conditions should contact their health care provider if fever occurs.
Because COVID-19 symptoms include fever, health care providers are now more concerned about temperatures that are somewhat higher than normal, Flais notes. A persistent low-grade fever is a reason to get COVID-19 tested.
“If a fever is lasting and it’s a child who’s not vaccinated for COVID, you would want them to get checked out for their own safety and to make sure they’re not a positive COVID contact for family members or community members,” Flais says.
Immunization can protect you from infectious conditions and resulting symptoms like fever. That includes routine childhood vaccinations and recommended adult vaccinations like the shingles series for adults ages 50 and older. Being fully vaccinated for COVID-19 and getting a COVID-19 booster shot if indicated is another way to avoid fever-producing illness.
More from U.S. News