How to Clean a Thermometer Because You Can’t Remember the Last Time You Did

thermometer cat

When you or your kids start to feel a little warm, you reach for the thermometer and think to yourself, err, have I ever actually washed this thing? Fear not, because we’re going to walk you through the quick and easy steps of how to clean a thermometer—no matter which kind you have—to knock one more thing off your “to-disinfect list” today.

Why it’s important to clean thermometers

If you’re regularly checking the temperature of everyone in your household to make sure no one as a fever of 100.4 or higher—the temp the CDC says you should tell your doctor about right away—you need to also ensure that the thermometer being passed around is clean. If not, it would be super easy for the bug you have to transfer to your kids, making your whole house sick.

1. Digital thermometer

The most convenient and widely sold thermometer on all of our pharmacy shelves these days is the digital thermometer. It’s fast, reliable, lasts an insanely long time (try to think about the last time its battery died. Bet you can’t!) and is a hotbed of germs once someone in your house is sick.

How it’s used

Basically a no-brainer, digital thermometers are turned on by pressing a button. Once it’s on, slide it under the tongue (as far back as it will gently go) of the person having their temperature taken and wait for it to beep before checking the digital screen to see the result.

How to clean it

To clean a digital thermometer, wash the tip and any part that was in someone’s mouth with soap and water for 20 seconds like you would your hands. Try not to get the half of the thermometer from the screen onward too wet since you can risk frying the battery and wrecking it for good. You can also wipe the whole thing down thoroughly with an alcohol-based wipe or the rubbing alcohol in your bathroom cupboard, as long as it’s at least 60 percent alcohol.

2. Temporal thermometer

This infrared scanner is gently swept across a person’s forehead so it can measure the temperature of their temporal artery, hence the name.

How it’s used

To use a temporal thermometer, the CDC came up with a set of steps that couldn’t be easier: Turn it on, slide it across the whole forehead of the person whose temperature you’re taking, pick it up and wait for the thermometer to give you a reading.

How to clean it

All you have to do to clean a temporal thermometer is wipe it with a clean paper towel dipped in rubbing alcohol (60 percent or greater concentration) or an alcohol-based wipe.

3. Ear thermometers

Typically used for babies under 3-years-old, ear thermometers are slipped gently into the ear canal to get a temperature reading without having to worry about your kid keeping her mouth closed for a whole 60 seconds—a true feat.

How it’s used

An ear thermometer only needs to be turned on and held in the ear of a child until it beeps. It’s also digital and has a quick and easy-to-read screen. No human error here. 

How to clean it

Since we’re working with another battery-powered thermometer, we’re going to resist submerging it in water in order to clean it and will instead grab the handy rubbing alcohol or a disinfecting wipe to clean it off once we’re through.

4. Anal thermometers

Also typically used on finicky babies who don’t want to deal with having a piece of plastic shoved in their mouths, anal thermometers are an option many parents prefer for their very young kids. It’s also the method that doctors say is the most reliable for infants, babies and kids age 0 to 5.

How it’s used

You’ll likely find on the packaging of most digital thermometers that they can be used anally or orally. So, just as we followed those very basic steps for the digital thermometer in spot number one on this list, we’ll heed the same advice for a rectal thermometer.

A disclaimer for this interchangeable tool: Any thermometer that’s used anally should remain an anal-only option. Yes, we’ll clean it, but the remote possibility—and very serious side effects—of passing fecal matter from your child’s butt to her mouth is enough to scare us off.

How to clean it

Unlike our other thermometer options, we’re going to clean the rectal thermometer once before it’s used and then again after it’s used to ensure it’s as clean as possible…because feces. Like we mentioned, this is another digital thermometer so we’re not going to dunk it in water. Instead, you can clean it by thoroughly scrubbing it down with a paper towel soaked in rubbing alcohol or with a disinfectant wipe. We fully support you if you feel the need to do this two (or three) times.

Regardless of the type of thermometer you and your family choose to use right now, it’s reassuring to know that there are quick and easy ways to clean it with products you probably already have on hand…and in ear, and on forehead and well, you know.

purewow author


From 2019-2020 Ariel Scotti held the role of Editor at PureWow covering trends, wellness and more.