A fever is one of the body’s best defenses against infection and a totally normal part of our awesome immune response. Typically, fevers will run their course with little or no treatment. But when your internal thermostat rises beyond the low-grade-fever range, it may be cause for concern and require medical attention.
What’s a normal body temperature?
We’re all conditioned to think of 98.6o F (37 o C) as a normal body temperature, but that number is just an average. (It’s also a result of a study done in the mid-1800s.) The reality is that most adults have a body temperature between 97o F to 99o F.
Body temperature can change throughout your life. Little ones tend to run a little hotter, and older adults register on the cooler side as their metabolism slows down. By stages, here’s how normal temperature ranges break down:
- Infant to 10 years: 95.9o F to 99.5o F
- Ages 11 to 65: 97.6o F to 99.6o F
- Ages 65 and older: 96.4o F to 98.5o F
What causes a fever?
In most cases, fevers happen because your body is trying to fight a viral or bacterial infection. And that’s a good thing.
Common fever causes include:
- Colds and flu.
- RSV (respiratory syncytial virus).
- Strep throat.
- Earache.
- Bronchitis.
- COVID-19.
- Urinary tract infection.
- Mononucleosis
In general, a temperature between 100.4oF and 102.2oF is considered a low-grade fever. Anything higher may be a sign of a more serious infection.
Fevers can also be caused by certain autoimmune diseases, such as lupus, rheumatoid arthritis and inflammatory bowel disease. Hyperthyroidism and other hormone disorders can also cause the body’s temperature to rise.
Illness and infection aren’t the only culprits. Fevers can also be a side effect of:
- Food poisoning.
- Stress.
- Extreme sunburn.
- Heat stroke and other heat-related illnesses.
- Certain medications, including antibiotics.
- Vaccines.
Why do vaccines cause fevers?
When you get a mild fever after a vaccine, such as a flu, COVID-19 or DTaP (diphtheria, tetanus, acellular pertussis) shot, it means your immune system is doing its job.
While a post-jab fever may leave you feeling lethargic and uncomfortable, rest assured you’re building immunity against the virus or bacteria the vaccine is designed to battle.
What are the symptoms of a fever?
An elevated temperature (over 100.4o F) isn’t the only sign of fever. Additional common symptoms include:
- Chills and shivering.
- Headache.
- Muscle aches.
- Sweating.
- Flushed complexion or hot skin.
- Fatigue.
- Loss of appetite.
How can I treat a fever at home?
If you or a loved one has a fever, there are some simple ways to bring down the heat and make bodies of all ages more comfortable.
- Drink plenty of fluids. When you have a fever, your body needs more water to compensate for its higher temperature. That can lead to dehydration.
- Get loads of rest. Your body is working hard to fight infection. Rest as much as possible to help it recover.
- Use over-the-counter meds. While medications are necessary to treat a fever, OTC remedies can help lower a fever and ease discomfort.
- For adults: Ibuprofen (Advil, Motrin), acetaminophen (Tylenol) or naproxen (Aleve).
- For children: Ibuprofen or acetaminophen (if your child is older than 6 months). Always avoid aspirin, which has been linked to Reye’s syndrome in children. The rare but dangerous condition can cause brain swelling and liver damage.
- Try a cool(ish) bath. A lukewarm bath can help cool the body. Despite popular opinion, a cold bath is not the way to go. It can cause shivering, which can elevate a fever even more.
- Dress lightly. Too many layers can trap body heat and cause temperatures to rise.
What should I do if I have a high fever?
Most fevers will go away on their own within a few hours to a day or two as your body battles infection. There are times, however, when you should seek medical care for a high temperature. Use the following guidelines to determine when care is needed:
- Infants and toddlers. When your little one heats up, it can be concerning. You should seek medical care if your child is:
- Younger than 3 months and has a rectal temperature of 100.4o F or higher.
- Between 3 and 6 months and has a rectal temperature higher than 102o F or has a lower temperature but seems unusually fussy, sluggish or uncomfortable.
- Between 7 and 24 months and has a rectal temperature higher than 102o F that lasts longer than one day but has no other symptoms. (Seek treatment for your child sooner if they show other symptoms, such as a runny nose, cough or diarrhea.)
- Younger than 3 months and has a rectal temperature of 100.4o F or higher.
- Children. If your kiddo is responsive, active and drinking plenty of fluids, a fever is likely not a cause for alarm. You should contact a health care provider if your child:
- Is lethargic or confused.
- Has symptoms that cause discomfort, including a severe headache, sore throat, vomiting, irritability or stomach ache.
- Has a fever that lasts more than 3 days.
- Has a seizure. If a seizure lasts longer than 5 minutes or your child doesn’t recover quickly, call 911.
- Is lethargic or confused.
- Adults. You should seek medical care if your fever:
- Stays above 103o F longer than two hours after home treatment.
- Lasts more than two days.
- Is accompanied by pain or burning when urinating. (You may have a UTI.)
Indigo Health can help take the heat off
While most mild fevers can be treated at home, Indigo Health is here to help when fevers don’t go away, get worse or come with other symptoms. Indigo makes it easy and convenient to get the urgent care you need when you need it.
Simply walk in or book an online appointment at one of our convenient neighborhood locations across Washington state. You can also schedule an online care visit to meet face-to-face with an Indigo provider. We’re here 8 am to 8 pm every day, including holidays.
One of our friendly providers will complete a physical exam, discuss your medical history and symptoms, and order additional tests, if needed. If your fever is due to a bacterial infection, your provider will prescribe antibiotics.
There are times when a fever requires emergency care. Visit your nearest ER when:
- A child under the age of 3 months has a temperature of 100.4o F or higher.
- Anyone with a temperature of 102o F is between the ages of 3 to 6 months, pregnant or immune compromised.
- Anyone of any age has a temperature higher than 103o
You should also visit your nearest emergency room if you have any of the following symptoms:
- Stiff neck
- Severe headache
- Skin rash
- Unusual sensitivity to light
- Chest pain
- Difficulty breathing
- Mental confusion or slurred speech
- Convulsions or seizures
- Severe vomiting or diarrhea with the presence of blood and dehydration symptoms (decreased urine, sunken eyes, lack of tears)
