Thermometer

These scan the temple to detect the temperature of the temporal artery. They are non-invasive and excellent for screening, though they may require more precise reading with a traditional thermometer if a high fever is suspected.

Reliable for adults and children who can hold the device correctly, notes MedlinePlus .

These use liquid crystals that change color to indicate temperature, often placed on the forehead, though they are generally less accurate than digital models. thermometer

These measure the infrared heat inside the ear canal.

All thermometers operate based on specific physical changes that occur when heat increases or decreases: These scan the temple to detect the temperature

Performed in the armpit; often used but less accurate, usually measuring lower than oral readings. If you'd like, I can:

Traditional bulb thermometers rely on the expansion and contraction of liquids (like alcohol or historically mercury) as temperatures fluctuate. As the temperature increases, the liquid expands and moves up the narrow, calibrated glass tube. These use liquid crystals that change color to

Over the next century, researchers refined this concept, shifting to liquids like wine, and eventually, alcohol and mercury. In 1714, Daniel Gabriel Fahrenheit developed the first true mercury-in-glass thermometer, providing a consistent, predictable tool with a standardized scale. The Celsius scale, or centigrade, was developed shortly after, basing measurements on the freezing ( ) and boiling points ( ) of water. How Thermometers Work