Yes, You Need to Clean Your Thermometer After Each Use—Here's How to Do It Safely

Learn how to disinfect digital and infrared thermometers to prevent the spread of germs between household members.

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When someone in your family feels sick, one of the first things you typically do is take their temperature. Fever is a common symptom for many illnesses, including influenza and COVID-19, making a thermometer an essential household tool, especially during a global pandemic. Because temperature readings often involve direct contact with a sick person, thermometers should be cleaned before and after each use. If multiple people are using the same device, you should both wash and disinfect the thermometer between uses to avoid passing germs between people. To make sure you're sanitizing it safely, follow these instructions for cleaning a thermometer, including digital and infrared versions.

close up of woman holding a digital thermometer
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How to Clean a Digital Thermometer

Typically the least expensive option, a digital thermometer ($10, Amazon) uses an electronic heat sensor to measure a person's body temperature in less than a minute. These can typically be used in the mouth, armpit, or rectum, but each device should be limited to one type of use to prevent cross-contamination. To clean a thermometer, you'll need rubbing alcohol with at least 60 percent alcohol, which is most effective at killing germs according to the Centers of Disease Control and Prevention (CDC). Then follow these instructions to clean and sanitize a digital thermometer before and after use:

  1. Soak a cotton ball or pad in rubbing alcohol and use it to thoroughly coat the entire device. Use a cotton swab dipped in alcohol to clean inside any small crevices.
  2. Allow the alcohol to air-dry on the thermometer to effectively kill germs.
  3. If desired, rinse the device under cool water to remove traces of alcohol, taking care not to wet any electronic elements, such as the display.
  4. Let the thermometer air-dry completely before using or storing.

Alternatively, you can wash the thermometer with soap and water, but take care not to submerge the electronic components, which could damage the device. You should also avoid using hot water to clean a thermometer, as this could damage the sensor that reads the temperature.

How to Clean an Infrared or Forehead Thermometer

This type of thermometer ($19, Amazon) uses an infrared sensor to measure body temperature in a few seconds through a forehead scan. Although many are designed to be used without touching skin, the device should be sanitized before and after use in case contact happens. Refer to the manufacturer's instructions for guidance on cleaning your specific model. Follow these basic steps for cleaning forehead thermometer:

  • Clean the thermometer's sensor with a cotton ball or pad soaked in at least 60 percent rubbing alcohol. You can also use a bleach wipe or alcohol pad ($4, Walmart).
  • Let the thermometer air-dry completely before using or storing.

Cleaning a thermometer is vital to avoiding the spread of germs between members of your household. With these tips, you'll be ready to take a safe, effective temperature reading whenever you need it.

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