Learn More About Thermometers


Learn More About Thermometers

Your Buying & Design Guide for Ordering Custom Thermometers What Are the Different Types of Thermometers? What You Can Use to Check Your Temperature How Do You Use a Thermometer? The Right Way to Take Temperature

You might think about fevers when you picture a thermometer, but they can be used for so much more. These little wonders can tell the temperature of a computer, pool, refrigerator, and even an entire building!

With all of these uses, it’s no surprise that there is more than one type of thermometer out there. Here’s a quick overview of everything you need to know!

What is a Thermometer?

Merriam-Webster defines a thermometer as “an instrument for determining temperature.” “Thermo” is a prefix related to heat, while “meter” is a suffix that’s used for any device that measures. A few other examples would be barometer, speedometer, and odometer.

What Are the Different Types of Thermometers?

Not every thermometer is made the same way. You can choose from any of the following types:

  • Digital
  • Mercury/Alcohol
  • Liquid Crystal
  • Meat/Food Thermometer


A digital thermometer is the most common type of thermometer and is generally considered to be the safest to use. It is either a traditional stick, or contains a probe on the end that can be scanned across the forehead. Either way, the temperature will be displayed on an easy-to-read screen.


The first mercury thermometers were invented in 1714. Mercury is a dense poisonous metal, which is why the Environmental Protection Agency (EPA) recommends that you handle this type of thermometer with great care.

Liquid Crystal

Have you ever seen a mood ring change colors? Liquid crystal thermometers work the same way! They are heat sensitive and contain a numbered panel that changes colors to show the temperature.

Meat/Food Thermometer

You can buy a special thermometer for cooking! A food thermometer sticks directly into your meat to ensure the internal temperature is fully cooked.

According to the U.S. Food and Drug Administration (FDA), this should be the minimum internal temperature for meat:

  • Beef: 140°F
  • Pork: 145°F
  • Poultry: 165°F
  • Fish: 145°F

Pro Tip: Does your temperature read 103°F? According to Mayo Clinic, a healthcare company in New York, it’s time to make a doctor’s appointment or visit a nearby hospital.

What is the Difference Between a Digital and Mercury Thermometer?

Both digital and mercury thermometers are fairly accurate, but a digital thermometer tends to be safer to use. You also don’t have to worry about cleaning up toxic materials if your digital thermometer breaks.

Here are all the differences between digital and mercury thermometers:

Here are the features of digital thermometers:

  • Digital thermometers rely on metal probes and electricity in order to work.
  • You can easily read the temperature since the numbers are displayed on a screen.
  • A digital thermometer provides faster results than a mercury thermometer.
  • It’s recommended that you use digital thermometers to take a child or baby’s temperature since they are safer to use.

Here are the features of mercury thermometers:

  • Mercury thermometers rely on the natural chemical reaction between mercury and hot or cold temperatures.
  • You read the temperature by seeing where the bar lands on the lines. The bigger line is 1°F and the smaller line is 0.2° F.
  • Mercury thermometers can withstand boiling and freezing temperatures, while digital thermometers may break in extreme conditions.
  • It’s dangerous if a mercury thermometer shatters on the ground since mercury is toxic.

Research is still being done as to the effects of mercury, but parents should note that it’s much safer to use digital thermometers for your children.

What Do You Do If Your Mercury Thermometer Breaks?

If your mercury thermometer breaks, do not panic. The Environmental Protection Agency (EPA) has created these easy-to-follow tips to make sure you stay safe:

Get your kids and pets out of the room immediately.

Open up a window and leave it open for at least 15 minutes.

Wear rubber gloves and old clothes to clean up the mercury beads and glass.

Collect the mercury beads with an eyedropper. Note: You should never use a broom or vacuum.

Use a flashlight to make sure that you have found all the beads.

If you still see small beads, put shaving cream on top of a paintbrush and “dot” the affected area. You can then use duct tape to grab those tiny beads.

Wipe the affected area with a damp cloth, making sure to get every inch.

Put the beads, your gloves, the duct tape, the eyedropper, and the cloth inside of a garbage bag. Tie the bag securely closed.

Contact your local health or fire department to find out how to properly dispose of the bag.

Let the room ventilate for the next 24 hours.

Are you still nervous about your broken thermometer? Reach out to your local position control center directly at 1-800-222-1222.

What Are the Different Ways a Thermometer Can Be Used?

A thermometer is designed to take your temperature in many different ways. In fact, there are thermometers that are designed for certain areas of the body.

  1. Axillary Thermometers (under your arm)
  2. Oral Thermometers (under your tongue)
  3. Tympanic Thermometers (in your ear)
  4. Rectal Thermometers (in your rectum)
  5. Temporal Artery or Infrared Thermometers (across your forehead)

Axillary Thermometer

Hopefully you’ve used deodorant because the axillary thermometer slides right into your armpit. Most digital thermometers can be used as axillary thermometers, so keep that in mind if you have one in your medicine cabinet.

Oral Thermometer

For the most part, a mercury or digital thermometer can be used to take an oral temperature. You can also find pacifier thermometers, which are designed for babies that are 3 months old or younger.

Tympanic Thermometer

Clean out that ear wax because a tympanic thermometer goes inside of your ear. This type of thermometer is typically small and has a probe at the end that goes into the ear canal.

Rectal Thermometer

It can be difficult to take the temperature of younger children since they don’t sit still. A rectal thermometer is a good solution and is often recommended for infants.

Temporal Artery Thermometer

A temporal artery, or infrared thermometer, has become extremely popular in recent years. It is very easy to use this kind of thermometer, and it’s also one of the more comfortable options.

The thermometers listed above can be digital or filled with mercury, alcohol, or liquid crystals. It just depends on the manufacturer! Be sure to read the package when you’re buying a new thermometer to see how it’s supposed to be used.

Which Type of Thermometer is Most Accurate?

According to Mayo Clinic, you will get the most accurate results if you use an oral thermometer. Make sure you’re keeping the thermometer under your tongue with your mouth firmly closed.

It’s also important to keep the thermometer in place for at least 30 seconds if you’re using a digital thermometer. You should avoid eating or drinking anything at least 20 minutes before you take your temperature for the best results.

Can I Use a Food Thermometer to Check My Body Temperature?

If push comes to shove, you can use a meat thermometer to take your body temperature. It’s definitely not as precise as a medical-grade or clinical thermometer, but it will do the job if needed.

The coronavirus (COVID-19) pandemic caused a huge shortage of digital and mercury thermometers in stores across the country. A meat thermometer became a good substitute during the crisis. If you use this method, make sure to keep the thermometer under your tongue and stay still. Contact your doctor asap if you have a high fever!

Can a Smartphone Be Used as a Thermometer?

Do you need to take your temperature? There’s an app for that! You’ll find options on both Android and iPhone that can track your fever.

The following apps will take your temperature and are available on both Android and iPhone:

  • Fingerprint Thermometer
  • iThermonitor
  • Real Thermometer
  • Smart Thermometer
  • Vick’s SmartTemp
  • Thermometer++
  • EasyBBQ
  • iCelsius

This isn’t an exhaustive list, but these apps are the most popular. They work via a digital scanner that reads your temperature when you place your index finger on the screen.

Please note, these apps may not be as accurate as glass or electronic scanners, so proceed at your own discretion. When in doubt, it’s always better to use a medically-approved thermometer to take your temperature.

Do Thermometers Expire?

Thermometers do not expire, but they do have to eventually be replaced. Digital thermometers will last about 3 to 5 years, while mercury thermometers will last indefinitely as long as they aren’t cracked or damaged.

Has your mercury thermometer stopped working? Stick it in the refrigerator or freezer! The cold will give the mercury a little jolt and might just fix the issue. If not, it might be time to look for a replacement!

Can You Recycle a Thermometer?

Thermometers are considered hazardous waste and cannot be recycled. Your best options are to wait for your community to have a Hazardous Waste Collection Day, or look for a facility near you.

If you can, avoid throwing hazardous waste in the garbage. This would include not only thermometers, but also lighters, pesticides, paints, batteries, and electronics like cell phones and televisions.

The Bottom Line

Thermometers are pretty genius inventions! You can easily see whether or not you have a fever, and there are many ways to check. Your health should always be #1 priority, so make sure you have a working thermometer in your house at all times.


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About the author

Alyssa Mertes

Alyssa is a promo expert with over four years of experience in the industry. She is the Lead Copywriter at Quality Logo Products and has had work published for the Promotional Products Association International and the Advertising Specialty Institute.