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Posted by Dr. Monica Wonnacott | January 23, 2016

How To Take A Temperature

Taking your child’s temperature is a straightforward process that, when done correctly, provides important information about your child’s health.

A normal temperature for a child is 98° to 99° F (37° C). A fever is a temperature greater than 100.4° F or 38° C.

Ways to take a temperature

There are multiple methods for taking a temperature:

  • Rectal (in a child’s bottom)
  • Oral (in a child’s mouth)
  • Axillary (under a child’s arm)
  • Ear
  • Temporal artery

Best way to take a temperature

The most accurate and consistently recommended method for taking a temperature is rectally. Do not fear the rectal temperature. It is the ONLY acceptable method for taking a temperature in an infant.

How to take a temperature

To take a rectal temperature, you need a digital thermometer (it will show numbers in a little window). You also need some lubricant (e.g., KY jelly, Surgilube, petroleum jelly, etc.). Here are the steps involved:

  1. Turn on the thermometer.
  2. Put some of the lubricant on the small end of the thermometer (the end with the silver tip).
  3. Lay your child across your lap or on something firm (e.g., a table). You can lay your child face up or down. If your child is face down, place one hand on your child’s back. If your child is face up, use your hand to hold your child’s legs up against his or her chest.
  4. Gently insert the lubricated tip of the thermometer half (½) an inch, just beyond the silver tip, into the child’s rectum. Use the same hand that inserted the thermometer to hold it in place and cup your hand over your child’s bottom to ensure the thermometer doesn’t get dislodged.
  5. After a minute, when it signals (e.g., beeps or lights up), read the number.

To take an oral temperature, you will also use a digital thermometer. Before taking the temperature, make sure that your child hasn’t had a hot or cold drink within the last 15 minutes – this can alter the reading.

  1. First turn on the thermometer.
  2. Put the small end of the thermometer (the end with the silver tip) under your child’s tongue as far back as it will go.
  3. Next, have your child close his or her mouth around the thermometer to hold it in place.
  4. After a minute, when it signals (e.g., beeps or lights up) read the number. (Again, keep in mind that a rectal temperature is more accurate than an oral temperature.)

There is some controversy over the accuracy of the axillary (armpit) temperature. Whether or not it is capable of measuring the core body temperature or just the skin temperature is the debate. For this reason, I am not going to review the methodology. By the way, did I mention that rectally is really the way you should be measuring your child’s temperature? J

How to read a temperature

A temperature is read like this: 100.4° is said “One- hundred-point-four degrees” and 104° is said “One-hundred-and-four degrees. Read it carefully. Parents relay these temperatures incorrectly all the time, and there is obviously a big difference between the two.