Here's How To Properly Take Your Baby's Rectal Temp, Because It's Incredibly Accurate

Dealing with a fussy baby is stressful, especially if you’re worried whether or not they have a fever. While you can sometimes tell if they have one by feeling their abdomen, it doesn’t give a precise number, which is important. You obviously can’t have your infant hold a thermometer in their mouth, but what if that type of thermometer is all you have available at the moment? You don’t want to waste time by running to the pharmacy at who knows what hour, so you should know how to take your baby's rectal temperature, just in case.

According to Parents, to properly take a rectal temperature, it’s important to first dab petroleum jelly or some other type of lubricant onto the bulb of the thermometer. Because if you don’t, yikes. Dr. Gina Posner, a pediatrician at MemorialCare Orange Coast Medical Center in Fountain Valley, California, tells Romper that next, you can lay your baby either on their back or their belly, but the back is probably easier for everyone involved. As far as how far you’re supposed to go in, Posner says, “You should just be putting the tip of the thermometer in, and then hold the buttocks closed over the thermometer.” The information in the Parents article agreed and suggested sliding the thermometer in gently about half an inch to one inch into your child’s bottom. Then, you should “loosely hold the thermometer in place with two fingers until it beeps.”

And taking your baby’s temperature through their bottom is even more accurate than their armpit or mouth. “The armpit is the second best — mouth usually cools down since a lot of times they are mouth breathing,” Posner says. Plus, I’d imagine it would be really difficult to get an infant to keep their mouth closed around a thermometer. Additionally, a Consumer Reports article agreed, and added, “An armpit temperature can be easier, but it's the least accurate. If the armpit temperature is above 99 degrees, double-check by taking a rectal temperature.”

If your child is above 3 months, and If you’re looking for other ways to take your baby’s temperature, Posner says there are many. “[There are] oral, rectal, axillary, and temporal [thermometers, as well as infrared [thermometers] now, too,” Posner explains. “Temporal is a thermometer that you scan over their head and to the temporal artery, and it is supposed to measure the temperature well.” An infrared thermometer is the kind that you stick in your ear.

Parents noted that you can switch to an oral thermometer once your child turns 3, otherwise either rectum or armpit it is. According to Consumer Reports, for children 3 and up, “Taking an oral temperature is OK, but some tots may have trouble keeping the thermometer in their mouths long enough to get an accurate reading.” The article recommended an ear thermometer as another option for older babies and children. “It gives quick results, but positioning it correctly can be tricky and you may not get the same temperature in both ears. Temporal artery thermometers, which read the infrared heat waves released by the artery in the temple along the side of the head, are acceptable for babies 3 months and older.” However, the article warned, “They are only OK as an initial screening device for younger babies — if there's any sign of fever, re-check it with a rectal thermometer.”

Though taking your baby’s temperature through their rectum may seem scary, parents do it all the time. As long as you lube the thermometer up really well, and only stick it in about half of an inch, your baby should be just fine. They may express their indignity for a few moments, but at least you have an accurate reading of their temperature, right?

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