Which temperature measurement site is described as most accurate?

• A. Oral (mouth)
• B. Tympanic (ear)
• C. Temporal (forehead)
• D. Rectal (rectum)

Answer: (B)

Temperature readings from different sites reflect core body temperature with varying accuracy, and technique strongly influences how close a reading is to the true core temperature. The tympanic route is described as the most accurate among commonly used noninvasive sites because the thermometer reads infrared heat from the tympanic membrane, which shares blood supply with the brain and closely mirrors core temperature. When placed correctly—aimed toward the tympanic membrane, with the ear canal clear of wax, and the device calibrated—it provides rapid results that are typically reliable and less affected by recent eating or drinking than the oral route. The key to accuracy is correct placement and ensuring the ear is free of obstruction; otherwise readings can be skewed by earwax, infection, or improper angle. While rectal temperature is often considered the most accurate core measure, tympanic readings are frequently described as the best noninvasive option when done properly.