Safety First Ear Thermometer 49659: How to Switch to Fahrenheit

There’s nothing more stressful than a sick kid at 2 AM — except maybe staring at a thermometer reading that says 38.5 and having absolutely no idea if that’s bad or not. That was me, about three years ago, fumbling with the Safety First ear thermometer 49659 Fahrenheit setting in the dark, half-asleep, completely confused.

If you’re here, I’m guessing you’re in a similar situation. Maybe your thermometer is reading in Celsius and you need Fahrenheit, or maybe you just picked it up and the safety first ear thermometer 49659 directions aren’t exactly jumping out at you from the packaging. Either way — I’ve got you. Let me walk you through everything I wish someone had told me.

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What Is the Safety First Ear Thermometer Model 49659?

The Safety First thermometer model 49659 is an in-ear (tympanic) digital thermometer designed for use in the ear canal. It’s a popular choice for parents because it gives a reading in about one second and works on kids and adults alike.

It uses infrared technology to measure the heat radiating from the eardrum, which is a pretty accurate reflection of core body temperature. It’s not a medical-grade clinical device, but for home use it’s genuinely reliable when used correctly.

Out of the box, some units default to Celsius — which makes sense for international markets, but if you’re used to Fahrenheit, it’s disorienting. The good news is switching is simple once you know how.

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Why So Many People Want to Switch to Fahrenheit

This is honestly one of the most searched questions about this thermometer, and it makes total sense. In the US, most people think in Fahrenheit. We know that 98.6°F is normal, 100.4°F is a low-grade fever, and 103°F means it’s time to call the doctor.

When your thermometer reads 39.2°C, you’re suddenly doing mental math at the worst possible moment. Is that high? How high exactly? That calculation delay adds unnecessary stress when you’re already worried about your child.

Additionally, if you share the thermometer with a pediatrician over the phone — “they have a temperature of 39.2” — there can be confusion on both ends. Having it display in Fahrenheit just removes one layer of stress from an already stressful situation.

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Step-by-Step: Safety First Ear Thermometer 49659 Directions to Change to Fahrenheit

Okay, here’s the part you actually came for. I’ll keep it straightforward.

What you’ll need: Just the thermometer. No tools, no app, nothing else.

Step 1: Make sure the thermometer is turned OFF. If it’s on, press and hold the power button until it shuts down completely.

Step 2: Locate the mode or unit button. On the 49659, this is usually a small button on the back or side of the device — sometimes labeled “MODE” and sometimes just a small recessed button you press with a pen tip.

Step 3: With the thermometer OFF, press and hold this mode button for approximately 5–8 seconds. You should see the display light up and show either “°C” or “°F” flashing.

Step 4: While it’s flashing, press the mode button once to toggle between Celsius and Fahrenheit. Select °F.

Step 5: Wait a few seconds without pressing anything — the thermometer will save the setting and turn off automatically.

Step 6: Turn it back on and do a quick test reading. It should now display in Fahrenheit.

That’s genuinely it. If it doesn’t work on the first try, make sure the thermometer is fully powered off before you start — that’s the step most people miss. I did it twice before I figured that out.

For the most current version of the safety first ear thermometer 49659 manual, you can also check the official Safety First website at [authoritative source: Safety First official site — safety1st.com] — they sometimes update the documentation for newer production batches.

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Reading the Safety First Ear Thermometer 49659 Manual — What You Need to Know

I know most of us don’t actually sit down and read a thermometer manual. But there are a few things in the safety first 49659 instructions that are actually worth knowing, because they affect your readings.

Probe placement matters a lot. The thermometer needs to be positioned correctly in the ear canal — angled slightly toward the eye on the same side, not straight in. An off-angle reading can be off by a full degree or more.

Wait 30 seconds between readings. If you take multiple readings back to back, the infrared sensor needs a moment to reset. Taking three readings in a row immediately can give you inconsistent numbers and freak you out unnecessarily.

Room temperature affects results. If you’ve just come in from the cold, give it 10–15 minutes before taking a reading. The ear canal temperature can temporarily drop after cold exposure.

Replace the probe cover every time. The disposable covers aren’t just for hygiene — they also affect the accuracy of the reading. Without one, you may get a slightly off result.

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Tips for Accurate Readings With the Safety First 49659

Getting a consistent, accurate reading is more about technique than the thermometer itself. Here’s what I’ve found works best after years of using this model:

Always use the same ear for consecutive readings. There can be a slight natural variation between ears, so switching sides mid-monitoring can make it look like the temperature is jumping around.

Take the reading after your child has been inside and calm for at least 10 minutes. Physical activity, crying, or recent outdoor time can temporarily affect the reading.

If you’re getting wildly different readings each time, check the battery first. A low battery is one of the most common causes of inconsistent results — and it’s the first thing to rule out before assuming the thermometer is broken.

For more on interpreting fever readings in children, [link to related post on fever management at home] has a really practical breakdown.

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Common Issues and Quick Fixes

Reading still showing in Celsius after following the steps? Try again with the thermometer completely off before you begin. Also, check if the battery is low — a weak battery can sometimes cause the device to not register setting changes properly.

Getting an “ERR” message? This usually means the probe wasn’t positioned correctly in the ear. Reposition, make sure you’re using a clean probe cover, and try again.

Temperature seems too low (like 96°F or lower)? The most common cause is incorrect angle — the sensor needs to face the eardrum, not the ear canal wall. Practice the slight forward tilt toward the eye on the same side.

Thermometer won’t turn on? Replace the battery (it uses a CR2032 coin battery in most versions). These batteries don’t last as long as you’d expect with frequent use.

Beeping patterns confusing you? One long beep generally means a successful reading. Multiple short beeps usually indicate an error. Refer to the safety first ear thermometer change to fahrenheit section above — if you accidentally changed a setting during troubleshooting, that’s an easy fix.

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Final Thoughts

Honestly, the Safety First ear thermometer 49659 is a solid little device once you understand how it works. The Celsius-to-Fahrenheit switch threw me off at first too — it feels like it should be obvious but somehow isn’t. Once it’s set to Fahrenheit, though, you probably won’t need to change it again.

Bookmark this page if you think you might need it again later. It’s one of those things where you’ll forget the exact button sequence in six months, and coming back here is faster than digging out the manual. Trust me, I’ve been there.

If you found this helpful, [link to related post on baby health essentials] might be worth a read too — I cover a few other tools I actually use and trust for monitoring kids’ health at home.

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Frequently Asked Questions

Q: How do I change my Safety First ear thermometer 49659 from Celsius to Fahrenheit? A: Turn the thermometer completely off, then press and hold the mode/unit button for 5–8 seconds until °C or °F flashes. Press the button to select °F and wait for it to save automatically.

Q: What does it mean when the Safety First 49659 beeps multiple times? A: Multiple short beeps usually indicate an error reading. Reposition the thermometer in the ear, replace the probe cover, and try again.

Q: Is the Safety First thermometer model 49659 accurate? A: For home use, yes — it’s reliably accurate when used correctly. Proper positioning in the ear canal and a clean probe cover are the two biggest factors affecting accuracy.

Q: How do I replace the battery in the Safety First 49659? A: The 49659 typically uses a CR2032 coin battery. Open the battery compartment on the back of the device, replace the battery, and make sure it’s seated correctly before closing.

Q: Can I use the Safety First ear thermometer 49659 on a newborn? A: Ear thermometers are generally not recommended for babies under 6 months because their ear canals are too narrow for accurate readings. For newborns, a rectal or temporal (forehead) thermometer is more reliable.