When taking an oral temperature using a glass thermometer, how long is it left in the patient's mouth?

When measuring oral temperature with a glass thermometer, the recommended duration for which the thermometer should remain in the patient's mouth is typically three minutes. This amount of time ensures that the thermometer can accurately reflect the core body temperature, as this duration allows the temperature sensor within the thermometer to equilibrate with the body's temperature.

Using a three-minute timeframe helps provide a balance between obtaining an accurate reading while also being practical for patient comfort. The glass thermometer relies on the expansion of mercury or other liquid within the glass tube, which needs sufficient time to respond to the temperature change in the mouth. A shorter duration may not allow enough time for the thermometer to reach a stable reading, potentially resulting in inaccuracies.

Overall, this standard of three minutes has been adopted to reflect best practices in clinical settings, ensuring reliable and consistent results when monitoring oral temperature.