Which method involves applying lubricant to the thermometer?

The method that involves applying lubricant to the thermometer is typically used when measuring rectal temperature. This practice is important for several reasons. First, applying lubricant helps ease the insertion of the thermometer into the rectum, making the process more comfortable for the patient. Additionally, the lubricant can help prevent irritation and trauma to the rectal mucosa during the measurement process.

In the case of rectal temperature measurement, it's crucial to ensure that the thermometer can be inserted smoothly and safely, which is why lubrication is a standard practice in this context. This method is often used in medical settings for accurate body temperature readings, particularly in infants or patients who may not be able to have their temperature taken orally.

Other temperature measurement methods, such as measuring axillary, oral, or aural temperature, do not require lubrication since they involve different techniques and anatomical areas where insertion and comfort considerations do not apply in the same way.