What is the most accurate method for measuring body temperature?

The most accurate method for measuring body temperature is rectal temperature measurement. This method is often considered the gold standard for several reasons. Rectal measurements are less affected by external environmental factors and produce results that reflect core body temperature more closely. This accuracy makes rectal measurements especially useful in clinical settings, particularly for patients who are critically ill, very young, or unable to take accurate measurements via other routes.

In contrast, oral temperature measurement can be influenced by factors such as recent food or drink intake, while axillary (or auxiliary) measurements are typically lower and less reliable due to the influence of external temperatures. Temporal artery temperature measurements, while useful for quick checks, may not provide the same level of precision as rectal readings due to variations in how the scanner may be used or positioned on the forehead. Therefore, rectal temperature measurements remain the preferred method among healthcare professionals for obtaining the most accurate assessment of a patient's core body temperature.