Monitoring health often involves using a thermometer, but the device can spread illness if not properly maintained. Cleaning removes visible debris, such as mucus or bodily fluids, from the surface. Disinfection is the next step, destroying pathogenic microorganisms that remain after cleaning. This two-part approach prevents the transfer of bacteria and viruses between uses, especially when the thermometer is shared or during contagious periods.
Cleaning Procedures for Digital Thermometers
The most common household thermometer is the digital probe style, used for oral, underarm, or rectal readings. Before applying disinfectant, the probe tip must be thoroughly cleaned with mild soap and cool running water. This initial wash physically removes organic matter, as disinfectants are less effective when applied to soiled surfaces.
After washing, use a clean, soft cloth or wipe to gently scrub the probe tip and the surrounding area near the display. Rinse the probe again with cool water to remove all soapy residue. While the probe tip is generally water-resistant, the electronic housing is highly susceptible to damage from moisture. Users must strictly adhere to the manufacturer’s immersion limits, which often mean the device should never be fully submerged.
If the thermometer is labeled as fully waterproof, a brief, full rinse is acceptable, but the device should be dried immediately. For non-waterproof models, carefully wipe the body with a slightly dampened cloth, preventing liquid from seeping into the battery compartment or display screen. Once physical cleaning is complete, the thermometer is ready for chemical disinfection.
Cleaning Procedures for Infrared and Non-Contact Devices
Infrared thermometers, including forehead and ear models, use sensitive optical lenses to measure thermal radiation. Unlike digital probe models, these devices must never be immersed in liquid, as moisture easily damages the electronics and sensors. Careful attention to the sensor lens is necessary, as it must remain spotless for accurate readings.
To clean the sensor, use a cotton swab or a soft, lint-free cloth lightly moistened with isopropyl alcohol or water. Gently wipe the lens with a side-to-side motion, avoiding excessive pressure that could scratch the surface. Some ear thermometers use disposable probe covers, and these should always be removed and discarded immediately after each use before cleaning the underlying sensor.
The exterior body of the non-contact device can be wiped down with a cloth lightly dampened with a mild soap solution. Ensure that no liquid drips or pools near the lens, seams, or button areas. Allow the entire device to air-dry completely before storing it, as residual moisture on the sensor can interfere with future temperature measurements.
Safe Disinfectant Selection and Application
The most common and effective agent for disinfecting thermometer surfaces is 70% isopropyl alcohol. This concentration is recommended because the presence of water allows the alcohol to penetrate microbial cells more effectively than higher concentrations, which evaporate too quickly. Disinfectant wipes pre-saturated with alcohol or other approved germicides are convenient alternatives.
After the initial physical cleaning, apply the chosen disinfectant to the thermometer surface using a clean cotton ball, swab, or wipe. The entire surface area to be disinfected must remain visibly wet with the agent for a specific duration, known as the contact time. While some product labels recommend a contact time of up to ten minutes, thirty seconds to one minute is often effective for common household pathogens.
Always consult the device manufacturer’s guidelines, as some plastics and coatings can be damaged by prolonged or repeated exposure to certain chemicals. Once the required contact time has elapsed, allow the disinfectant to air-dry completely before placing the device back into its protective case. Proper storage in a dry location, away from direct heat and out of the reach of children, helps maintain the device’s accuracy and integrity.