Why is body temperature can be measured by keeping thermometer under the tongue?

Body temperature can be measured by keeping a thermometer under the tongue due to the rich blood supply in this area. The tongue is located close to the carotid and jugular blood vessels, which transport blood to and from the heart, respectively. This constant blood flow helps maintain a relatively constant temperature in the tongue.

When a thermometer is placed under the tongue, it comes into contact with the warm blood, and the mercury or digital display on the thermometer rises accordingly. This temperature measurement represents the core body temperature, which is the temperature of the internal organs and reflects the overall thermal state of the body.

This method of measuring core temperature is non-invasive, convenient, and provides a reasonably accurate approximation of the body's internal temperature. However, it is important to note that the precise temperature reading may slightly vary depending on factors such as the placement of the thermometer, the brand or type of thermometer used, and individual variations in anatomy and circulation.