Why do you put a thermometer under your tongue?

Putting a thermometer under the tongue is a common method for measuring body temperature because the temperature of the blood flowing through the tongue reflects the core body temperature. Here's why it's an effective way to measure temperature:

1. Accessibility: The tongue is easily accessible and convenient for temperature measurement. It allows for simple and quick placement of the thermometer.

2. Good Heat Transfer: The tongue is rich in blood vessels, ensuring good heat transfer between the blood and the thermometer. This means the temperature reading from the tongue closely reflects the internal body temperature.

3. Accuracy: When used correctly, placing the thermometer under the tongue provides accurate temperature measurements. The temperature reading obtained is generally considered to be reliable and can be compared to readings from other methods, such as axillary (underarm) or rectal measurements.

4. Standardization: Measuring temperature under the tongue has become a standardized method, allowing for comparison of temperature readings across individuals and healthcare settings.

However, it's important to note that certain factors can affect the accuracy of oral temperature measurements, such as mouth breathing or eating or drinking hot or cold substances before the measurement. It is recommended to follow the manufacturer's instructions for proper use of the thermometer and to be aware of any factors that may influence the temperature reading.