Digital thermometers: what to buy and how to use

As we head into autumn, children go back to school and the season of coughs and sneezes begins, a thermometer is a useful piece of kit to have to hand to keep tabs on your health. If you’re looking to buy a thermometer, we’ve rounded up our expert tips on choosing the best type, typical prices and how to use them properly. The advice on this page is primarily aimed at adults wishing to take their own temperature.

Types of thermometer: which is best?

If you’re shopping for a thermometer, you’ll find yourself having to decide between various types. Here’s a quick run down of the pros and cons of the different types:

Digital thermometers (typically £5 to £10)

These are the most common type of thermometer and a good basic option. They should produce accurate readings when used correctly. You can place the thermometer under your armpit, but you’ll get a more accurate reading from the mouth, where it should sit under the tongue. The only real disadvantage is that it can be a bit uncomfortable to sit with it under your tongue for several minutes and you’ll need to take care to clean it between uses. Try to steer clear of old-style mercury thermometers – mercury is toxic and will be a pain to clean up if you end up breaking it accidentally.

Digital in-ear thermometers (typically £20 to £40)

Ear thermometers are quick and easy to use, taking just a few seconds to get a reading – using infrared technology to measure the temperature inside your ear. You may get an inaccurate reading if the device isn’t positioned correctly in the ear or if there’s a build up of earwax. They’re pricier than digital thermometers, but might be a better option if you want a quick solution, or are trying to take the temperature of a child who doesn’t like to sit still for long.

Non-contact thermometers (typically £30 to £70)

As the name suggests, with no-contact thermometers you don’t need to press the device against your skin or place it in your mouth. These thermometers use infrared technology to detect heat coming from the surface of your skin. Noncontact thermometers tend to be more expensive, but if you’re looking for a non-invasive way to check a temperature and want to avoid the faff of cleaning the thermometer between uses, they can be a good option.

Take your temperature using a smartphone

You can get a small plug-in device that, when hooked up to your smartphone via the headphone jack, turns it into a digital infrared thermometer. To record a temperature, you simply place the gadget on your forehead or in your ear. Readings taken from the thermometer are fed into the smartphone app, which stores results so you can track changes.