What’s the most common cause of fever, in both adults and children? Viruses, such as the cold or flu; airway infections like croup or bronchitis, and stomach bugs are the usual culprits. While these illnesses make you feel miserable, the good thing is they’re usually not serious and resolve on their own.

How hot is hot?  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 degreesC), 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.

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.

Ugh, 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. Certainly, 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.

Worse, the kid’s sick!  What should I do?  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.

How about older children?  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.

What’s next?  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: 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!

David Davis

About the Author: 

David Davis, MSN, APRN, FNP-C is a family nurse practitioner and retired Naval Officer.  Dave sees patients at the Portsmouth Family Medicine offices on Tuesdays, Wednesdays, and Fridays, and at the Lifespan Physician Group, Primary Care, Newport offices on Mondays and Thursdays. 

He can be reached at (401) 683-3300 in Portsmouth and in Newport at (401) 606-4510.

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Ryan Belmore has been the Owner & Publisher of What's Up Newp since 2012. He also currently works for Mountain News, where he serves as Senior Editor - North America for OnTheSnow. He previously worked for the New England Patriots and American Cancer Society. He currently serves as Vice President of Fort Adams Trust and is a member of Local Independent Online News (LION) Publishers and North American Snowsports Journalists Association (NASJA).