Fever and Body Temperature
With the cold and flu season upon us, what better time to talk about temperature and that rise in body temperature known as fever.
What causes a fever?
The most common cause of fever in both adults and children are infections such as the cold or flu, airway infections like RSV, croup or bronchitis, and stomach bugs. While these illnesses make you feel miserable, the good thing is they’re usually not serious and resolve on their own.
What temperature is considered a fever?
It depends on how you take a temperature. A temperature taken by mouth over 100 degrees F (37.8 degrees C) is considered a fever. Armpit temperature over 99 degrees F (37.2 degrees C), or rectal, ear or forehead temperature over 100.4 degrees F (38 degrees C) are also all considered fever. And while armpit, ear and forehead temperature is the easiest to measure, the most accurate means of measuring fever is with an oral or rectal thermometer.
What is the right way to take a temperature?
First, clean your thermometer with soap and water and wait 30 minutes after eating or drinking something hot or cold. When taking a temperature by mouth, make sure the thermometer is under the tongue and held in place by the lips, not the teeth. Digital thermometers are quick, but you should wait three minutes for a glass thermometer to obtain an accurate reading.
I’ve got a temperature. Should I call my primary care provider?
Yes, if you’re an adult and just back from overseas or the hospital, or you’re on chemotherapy or an immune system suppressing medication such as steroids. If the fever just won’t go away, or you have a chronic illness such as heart disease or sickle cell anemia, it’s time to call. And a fever accompanied by rash, severe head, neck, or belly pain, vomiting or diarrhea warrants a phone call or contact via the MyLifespan portal.
When should you worry about a child's fever?
If your child is less than three months old and has a rectal temperature over 100.4 degrees F (38 degrees C) you should see your provider. If the child is under three years old and has a fever over 102 degrees F (38.9 degrees C), or the fever is over 100.4 degrees F (38 degrees C) for three days you should also see your provider. In any case, if your child’s behavior is far from the norm or if the child refuses to drink fluid, bring them in.
Older children and fever
At any age, a child with a temperature over 104 degrees F (39.4 degrees C), or who has a seizure or chronic medical problem or has a new rash as well as the fever, should visit their primary care provider.
How are fevers treated?
You may not be prescribed antibiotics, since they work only on bacterial infections and many fevers are caused by viruses. Most fevers need nothing further than treatment of the symptoms. Your primary care provider may prescribe Tylenol or Advil for comfort, but even that may not be necessary.
A child over three who is otherwise behaving normally may not need any treatment at all, and remember to never give a child under 18 years old aspirin, which can cause a dangerous condition known as Reye Syndrome.
The best thing for when you have a fever? Rest, drink plenty of fluids, and stay home!
About the Author:
Lifespan Physician Group Primary Care Team
Lifespan Physician Group Primary Care Team provides crucial services for your long-term health and well-being at several locations in Rhode Island.
Lifespan Living Newsletter
Find a Doctor
The right provider is in our network
Search more than 1,200 providers in our network.