Taking Your Newborn’s Temperature

What, How, Why?

A temperature of 100.4 or greater is considered a fever.

As a new parent, nothing spikes your anxiety quite like your newborn feeling warm to the touch. "They feel warm" can be a relative statement. To be certain and confident in determining your next steps, below is a guide of what to use and how to take your baby's temperature.

Newborns have new and developing immune systems. If your baby has a fever, it is a sign their body is under stress in some capacity. We especially want to be proactive to avoid our babies getting to and or prolonging this stressed out state.

Taking your newborn’s temperature accurately is one of the most empowering skills to learn. Knowing you’re getting a reliable reading at home can make the next steps easier to decipher. Ultimately, this can alleviate concern and prevent further anxiety.

Keys to success when taking your newborn's temperature

• Why choose rectal temperature?

• Tips to build confidence

• What about other methods?

• A Quick Note on the ER (When to Go)

Why Choose Rectal Temperature

A rectal temperature is considered the gold standard as it is the closest to your baby’s core temperature. In other words, this is the most accurate temperature you can take. With the level of seriousness a fever can mean, an accurate reading is of the utmost importance- being off by just a degree can dramatically impact your next steps. This can help avoid unnecessary concern and trips to seek further assistance from a medical professional, such as reporting to the ER. 

What you’ll need in order to take your baby's temperature rectally.

• Digital rectal thermometer (when purchasing it should be labeled as “rectal only”; Some thermometers are for rectal, ear, forehead and armpit or under the tongue)

• Petroleum jelly (Vaseline, Aquaphor, etc) (optional)

• Soap and warm water (for cleaning)

Step-By-Step Guide:

• Wash your hands and clean the thermometer

• Place a small dab of petroleum jelly on the tip (optional)

• Position your baby-

Option A (on their back): Lay baby on their back on a firm surface - such as their changing pad. Gently hold both ankles and lift legs toward their chest - just like a diaper change!

Option B (on their belly): Lay baby tummy-down across your lap, one hand resting on their lower back for stability.

• Gently separate the buttocks and insert the lubricated tip ½ inch and no further than 1 inch into their rectum. Typically it is the length of the silver part at the end of the thermometer. 

• Hold the thermometer in place until it beeps (usually 10-30 seconds; some thermometers are much quicker!)

• Remove (Careful! They might poop a little), wipe clean, and read the display. 

• Clean the thermometer with soap and water

Tips to Build Confidence

1. Practice rectal temps during calm, happy diaper changes - No stress, just skill building

2. Wait 15-30 minutes after a bath, feeding, or heavy bundling before checking

3. Start with two people - babies can be squirmy! The extra hands will be helpful as you get a feel for how to move through the above steps smoothly.

What about other methods?

EAR, FOREHEAD, and ARMPIT (or UNDER THE TONGUE) are all additional options for taking your baby's temperature. Here are some considerations to support forgoing those methods during the infancy stage. Note- Using whichever method you are most comfortable with beyond the infancy stage is recommended.

EAR: Not recommended due to tiny ear canals under 6 months. This and wax buildup can lead to unreliable readings.

FOREHEAD: Not recommended due to the very specific way to use and lots of room for error based on model purchased, pressure, and variability of placement on their forehead. 

ARMPIT: Not recommended due to it consistently reading lower than core temperature. Placement is key for this method and your baby's fat percentage can affect the reading.

A Quick Note on the ER (when to go)

For any baby under 3 months with a rectal temperature of 100.4 or higher, call your pediatrician. In the event that this happens beyond normal business hours and you can't get ahold of your provider, we recommend discussing this situation at one of your first appointments to have a better idea of what their recommended course of action would be. In infants less than 60-90 days old, a fever is taken very seriously. 

Red Flag symptoms eliciting an immediate ER visit :

• Extreme lethargy (your baby is harder to wake up for feeds compared to prior wakings)

• Poor feeding (skipping a feed)

• Fewer wet diapers (dry diaper for 6 hours or greater)

• New rash

• Trouble breathing (when laying flat, their chest is lifting off the flat surface)

• Pale or Blue appearing lips and or gums 

• Constant high-pitched crying

What should I anticipate the ER visit to look like?

In the ER, expect prompt triage (initial assessment to determine how quickly you need to be seen), a full exam, and often a “sepsis workup”. This typically includes taking your baby's blood, collecting a urine sample, and sometimes obtaining a sample of their spinal fluid. Most babies tolerate this testing beautifully, but, it can be hard for parents to witness all the poking and prodding.

How can I best support my baby if we have to go to the ER?

In terms of comfort, we recommend bringing the following:

• Pacifier

• Swaddle/Swaddle Blanket

• If not breastfeeding, breastmilk or formula for bottle feeds and bottles, pump, and pump parts for 2-3 feeds. (You may be there for awhile and you can always call your support system to bring more if needed beyond the 2-3 feeds.)

Remember -Trust your instincts. You’ve got this! Equipping yourself with accurate temperature taking skills can be so beneficial in the early months. Your pediatrician is there for you and knows your baby. Run any medical questions by them and as needed.

***Information given by Fourth Trimester Training in this blog, marketing material or other company-created work is not medical advice, and is given for informational purposes only. This information is not intended to diagnose, treat or prevent disease. Any information provided by Fourth Trimester Training is not intended to be a substitute for medical advice, and Fourth Trimester Training encourages you to use any information provided by Fourth Trimester Training only in consultation with a medical professional.