Everything you need to know about thermometers

By Eliza Henry-Jones

During the COVID-19 pandemic, you might be wondering about thermometers. From glass and mercury through to smart thermometers with their very own apps, this article has you covered!

Mercury Thermometers

You’ve probably heard of (or seen) mercury thermometers, which were invented in the 1700s. These glass contraptions have a thin line of mercury, which expands when heated. Given the toxicity of mercury and the fragility of glass, they’re no longer recommended for measuring body temperature.

Ear Thermometers

Ear thermometers rest in the ear in order to measure body temperature. There’s a bit of controversy about whether they should be used in children under six months. When using an ear thermometer, watch out for a build up of ear wax (which can alter the reading) and be careful of how far you put the reader into the ear canal.

The cost of ear thermometers varies. For instance, the Omron TH839S Ear Thermometer is $59.99 from Chemist Warehouse, compared with the Safety 1st Easy Read Ear Thermometer, which is $24.99 from Target.

Forehead (Temporal) Thermometers

These thermometers need to be moved across the forehead to get a reading and can be used on children from birth. Although potentially not as accurate as a rectal measurement, they’re far less invasive.

While basic models will set you back about $49.95 (the Oricom IR Thermometer from BubMania), you can purchase smart forehead thermometers which link to your phone or computer, allowing data to be saved for the whole family. For instance, when using the Withings Thermo Smart Temporal Thermometer, the measurements will sync automatically with your iPhone or iPad. Based on the age, fever history and symptoms of the person being measured, the Thermo app will even give you health advice. This thermometer is available from the Apple store for $179.99.

Digital Thermometers

Digital thermometers are relatively cheap and can be used rectally, orally and under the arm. Obviously, if you’re planning to take both oral and rectal temperatures, make sure you purchase two thermometers and have them clearly labelled! Digital thermometers can be used under the arm from birth and – like temporal thermometers – are much less invasive than oral or rectal measurements. Digital thermometers are the cheapest option – you can purchase a Vicks Insight Thermometer for $21.49 from Chemist Warehouse.

If you’re unsure about what thermometer might suit you or how to use them effectively, give your family doctor a call!