One pacifier thermometer even plays a lullaby whenever fever is detected. In fact, many pediatricians consider rectal readings the gold standard of temperature-taking. Like oral models, rectal thermometers are available in both mercury-glass and digital models. Rectal readings are usually one degree higher than temperatures taken orally. The underarm is the least invasive site for temperature-taking.
Underarm readings are usually one degree lower than temperatures taken orally.
The most advanced electronic models make this conversion automatically. These sophisticated underarm thermometers employ advanced infrared technology to take a succession of rapid readings. They then utilize an internal computer to calculate body temperature with a level of speed and accuracy that is unavailable with other devices. However, medical research has proven that normal temperature varies from person to person and that in every individual, temperature fluctuates throughout the day. And so, there is no one single ideal normal temperature.