How to take baby’s temperature

This post is brought to you by Kinsa.

As a new parent, you have a lot to worry about, and we know your child’s health often tops the list. The best indicator of sickness is sign of fever, so it’s important to know how to accurately monitor your baby’s body temperature.


Any level of fever can be a sign of infection at this highly susceptible age, so you want to take baby’s temperature often and ensure you’re getting an accurate reading. Pediatricians recommend rectal temperatures as the most precise for newborns. Often, parents keep a temporal or underarm thermometer around for a quick read and resort to the rather unglamorous rectal temperature taking if it seems high. To take a rectal temperature:

1. Disinfect the thermometer with an alcohol swab.

2. Consider applying a bit of petroleum jelly on the end to make it easier to insert.

3. Place your baby on your lap or a firm surface, on his stomach or on his back with legs lifted in diaper-changing position.

4. Insert the tip of the thermometer ½-inch to 1-inch inside his anal opening. Hold it in place between 2 of your fingers while cupping your hand around his bottom until reading is complete.


It’s a good idea to get in touch with your doctor immediately if babies less than 6 months old show signs of fever. According to the Mayo Clinic, fever is considered mild if rectal temperature reads 100.4-102 degrees F, moderate if temperature reads 102-103, and high if temperature reads above 103.


Toddlers are notoriously hard to keep still. Once your child is on the move, getting them to sit for a rectal temperature reading is a difficult task. An ear temperature reading may be a better bet in this case. To take an ear temperature reading:

1. Disinfect the tip of the thermometer (an alcohol swab will do the trick). Turn it on.

2. Gently place the tip in your child’s ear canal facing down and back.

3. Press the button with your thumb to take the temperature, and remove the thermometer when it beeps.

Another option is an oral or underarm temperature reading. Often, general stick thermometers can be used for oral, underarm or rectal temperatures. For an oral temperature:

1. Disinfect the thermometer with an alcohol swab.

2. Make sure your child doesn’t eat or drink anything hot or cold for 15 minutes before the temperature reading.

3. Place the tip of the thermometer under your child’s tongue, toward the back of the mouth.

4. Make sure your child keeps his or her mouth closed for the entire reading.

Take note of any changes in temperature or any symptoms your child exhibits so you can give your doctor the best information for a more informed diagnosis.

The Kinsa Smart Thermometer is the first-ever FDA-cleared smartphone-connected thermometer available on the market. The smart stick and smart ear thermometers take accurate temperature quickly, and the free Kinsa app tracks illness history for each member of the family while offering guidance on what to do next. Kinsa is ready to help whole communities better track, treat, and stop the spread of illness.