A fever is often a reaction to viruses and germs so make sure you have a thermometer at home so you can spot any warning signs early. This is especially important for families with babies and children where taking a temperature check every day is common. So how do you choose the right thermometer?

Factors to Consider

1. Precision & Safety

There are four main types of thermometers. Listed in order of precision they are: mercury, electronic, ear and forehead.

The most accurate is the mercury thermometer which in fact is made of glass. However, it breaks easily and the mercury inside is toxic and should never be used to measure a child's body temperature.

In recent years, medical institutions in many countries have stopped using mercury thermometers due to environmental and safety concerns and replaced them with electronic thermometers and ear thermometers. Results show that these new types of thermometers are pretty reliable.

For the average family, the temperature of a fever is only a reference to give you a preliminary idea of the person’s health before deciding whether to seek medical attention or take other measures. In this case, a certain margin of error is acceptable. As long as it is used correctly, an ear thermometer which is more convenient to use is just as reliable as a more versatile forehead thermometer and suitable for use at home.

2. Degree of convenience

The accuracy of the electronic thermometer is comparable to that of a mercury thermometer. It is contact-based and takes longer to measure. For example, an oral probe takes 2 to 3 minutes to complete. This is fine for adults, but is not as easy for children as they often can’t sit still. It is not convenient when used to measure temperature in the mouth, armpits and anal area as it the thermometer needs to be cleaned and disinfected after each use.

Ear thermometers, on the other hand, are equipped with ear covers which are safe, hygienic and reduce the need for cleaning and disinfection each time.

Even for models that do not require ear covers, can be simply disinfected with alcohol before use. An ear thermometer measures the temperature of the ear drum which has the same blood supply as the inferior colliculus, the part of the brain responsible for regulating body temperature. This means it can accurately reflect changes in body temperature. Some models can calculate the fever threshold according to the age of the person being measured and have a special function to reduce the margin of error.

It is important to note that the human ear canal is not straight. When taking the temperature of an infant under the age of 3, the ear canal should be lifted gently in a downward direction, while over the age of 3, the ear canal should be lifted in an upward direction to ensure the ear thermometer is placed in its correct position.

3. Other features

You are reminded that the ear canal of babies under 6 months is small and therefore not suitable for an ear thermometer. Topical thermometers offer a better choice as these can be used without disturbing the child or patient as the temperature is measured using a non-contact method.

Note that a forehead thermometer has a large margin of error. It’s important to know how to use it properly. Make sure there are no hairs, a hat, sweat, or grease on your forehead, and then measure at a distance of about 2-5cm from your eyebrows.

Some models have distance reminders to make the forehead thermometer easy to use. Because it uses infra-red technology, it can be used as a general thermometer to measure the temperature of objects, liquids and different environments, making it a multi-purpose device.