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Fever in Babies

Welcoming a new baby into your home can be an exciting, but nerve-wracking time for parents. The nerves are understandable, considering that newborns don't come with instruction manuals, and babies aren't like little adults when they're sick -- they need special care.

A fever in babies can be one of the scariest symptoms for parents, especially when that fever is high or the baby is only a few weeks old.

In this article, you'll learn what causes infant fevers and what to do when your baby gets a fever.

What Causes Infant Fevers?

A fever isn't an illness -- it's a symptom of one. Usually if your baby has a fever, it means he has picked up a cold or other viral infection. Less commonly in infants, a fever is a sign of a bacterial infection such as a urinary tract infection or a more serious infection such as meningitis. 

Other causes of fever in babies include:

  • Reaction to a vaccination
  • Becoming overheated from being dressed too warmly or spending time outside on a hot day


Fever in Babies: What Are the Signs?

One common sign of fever in babies is a warm forehead, although not having a warm forehead doesn't mean that your baby doesn't have a fever. Your baby may also be crankier than usual.

Other symptoms associated with fever in babies include:

  • poor sleeping
  • poor eating
  • lack of interest in play
  • lethargy
  • convulsion or seizure


How Do I Take My Baby's Temperature?

You can take a child's temperature a few different ways, such as via the rectum (rectally), mouth (orally), ear, under the arm (axillary), or at the temples. The American Academy of Pediatrics (AAP) recommends only using digital thermometers in children. Mercury thermometers should not be used because they pose a risk of mercury exposure and poisoning if they break.

Rectal thermometers provide the most accurate temperature readings, and can be easiest to take in an infant. Typically, babies can't hold an oral thermometer in place, and the reading of an ear or underarm thermometer are not as accurate.

To take a rectal temperature, first make sure the thermometer is clean. Wash it with soap and water or wipe it off with rubbing alcohol. Lay your baby on the belly or on the back with legs bent into the chest. Apply a little bit of petroleum jelly around the thermometer bulb and gently insert it about 1 inch into the rectum opening. Hold the digital thermometer in place for about two minutes until you hear the "beep." Then gently remove the thermometer.

At What Temperature Does My Baby Have a Fever?

A baby's normal temperature can range from about 97 degrees Fahrenheit up to 100.3 degrees Fahrenheit. Most doctors say a rectal temperature over 100.4 degrees Fahrenheit is considered a fever.

WebMD Medical Reference

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