No, it doesn’t. That’s the beauty of simpler instruments – they rarely malfunction or stop working. More complicated the instruments you see, more will be their chances of leaving you stranded. The simple clinical thermometer is essentially just a capillary tube with mercury inside it.

A thermometer is the instrument used to tell the air temperature. A thermometer is usually made up of a small, hollow glass tube. At the bottom of the tube is a bulb, which holds a liquid such as alcohol or mercury. When there is an increase in heat, the liquid inside the bulb expands, pushing up into the tube.

The small silvery ball in a mercury thermometer can be dangerous if the glass breaks and the mercury is not cleaned up properly. The mercury will evaporate and can contaminate the surrounding air and become toxic to humans and wildlife. Each thermometer contains about . 5-1.5 grams of mercury.

Oral and axillary temperature readings are about ½° to 1°F (. 3°C to . 6°C) below rectal. Add these numbers to oral and axillary temperature readings for the most accurate reading.

As a reference, the average normal oral temperature is established as 98.6°F (37°C). Rectal temperature is 0.5°F (0.3°C) to 1°F (0.6°C) higher than an oral temperature. Ear (tympanic) results may also be 0.5°F (0.3°C) to 1°F (0.6°C) higher than an oral temperature.

The axillas are not normally exposed to the environment so axillary temperature varies less than exposed skin temperature. However, most axillary skin and tissues are not close to major blood vessels, so axillary temperature is as much a reflection of skin temperature as of core temperature.

Infrared thermometers might be ‘hygiene theatre,’ but they won’t harm your brain.

Since infrared forehead thermometers are used to measure human body temperature, they should be FDA approved for clinical use, like the 67 MAX. If you don’t have this adjusted mode you get a reading that’s about 3 °C (5.4 °F) low, because of the difference between skin and body core temperature.