Taking the temperature of a young child can sometimes turn out to be an arduous task, particularly with different thermometers and methods now available. Being aware of the various options available, their pros and cons, the detailed steps required therein and the precautions to be taken can be helpful.

Taking temperature of a child is a part and parcel of modern child care that all parents, baby sitters and child care providers need to be familiar with. For a first timer, it can be challenge and hence it is important to be aware of all aspects, including the types of thermometers and the various methods which can be used. Even for experienced persons, it may not be a bad idea to review and update their knowledge once in a while to ensure they do not make any mistakes and are aware of all options available with them.

Types of Thermometers

There are different types of Thermometer which can be used in different ways to take the temperature of the child.

Mercury Thermometers should Not be Used

The older Mercury thermometers should not be used because of the risk of exposure of child to Mercury which is a toxic substance. In fact, the American Paediatric Association recommends not keeping any mercury thermometers in the house so as to avoid any accidental poisoning from their use.

Digital Thermometers are the Choice Now

Digital Thermometer is generally the most preferred option. It is accurate and reliable, and can be used for children for most age groups. It is important to read the manufacturer's instructions, and be very clear about the minimum exposure time for recording the temperature.

Usually a beep or two will indicate that the thermometer can now be read. Many digital thermometers come with disposable sleeve which should be discarded after use. Before measuring temperature, one must also ensure that the last reading is deleted.

A number of different digital thermometers have now become available, which can be used for different methods of taking temperatures. These include the regular thermometer, used for oral, rectal and axillary (arm pit) methods, which are available with glass tips as well as plastic tips. Those with plastic tips are safer for younger and uncooperative children. In addition now, the forehead thermometers and the tympanic or ear thermometers are also easily available, though a little more expensive.

Each of them comes with its own pros and cons in terms of accuracy, convenience and price. Most can be used, provided you know their pros and cons and how and when they should be used. One must remember that different methods can lead to different temperatures and the threshold of considering the temperature as fever differs from method to method.

Different Methods of Recording Temperature

Temperature of a child can be taken using a digital thermometer in many ways. These are the rectal method, oral method, axillary or armpit method, forehead method and the tympanic or ear method. The first three can be taken by a regular oval digital thermometer, while specialized and slightly expensive thermometers are required for the last two of them.

Among these methods, the rectal method is the most accurate method and recommended in children less than 4 years. Above the age of 4 years and if the child is cooperative, the oral method, which is also accurate, can be used. The axillary or armpit method is relatively less accurate and hence not the recommended method, but can be used in all ages, is convenient and hence preferred for screening purposes.

The forehead and ear methods are more recent and though they are convenient and have reasonable accuracy, they are still not standardised enough to be preferred for medical experts, who only opt for the most accurate and are unwilling to tolerate any inaccuracies. One can say that their acceptance as the standard method is still under process and not yet completed.

RECTAL METHOD

This method involves inserting the tip of the thermometer into the rectum or the bottom of the child. To those with no past experience, it may appear somewhat challenging but it is not that difficult. It is the most accurate method, and hence preferable when accurate reading is required. It is the method of choice up to the age of 3 months and can be used depending upon need till the age of 4 years. Beyond that age, the child can usually cooperate to take oral temperature, and hence it is not recommended.

Steps in taking temperature by Rectal Method

• To avoid accidental use of same thermometer for both rectal and oral methods, before taking rectal temperatures, the digital thermometer should be properly labelled as 'Rectal thermometer'.

• Place some lubricant or jelly on the tip of the thermometer. 

• Lay the child on the back and bend his legs to the chest. Alternatively, place the child on the belly (back up) on your lap or on a fixed surface. Hold him in a firm position by placing your palm on his lower back just above the bottom.

• Gently insert the thermometer half to one inch into the anal opening with the other hand. Do not insert too far or too hard and stop immediately if you feel any resistance. Keeping your hand cupped around your child's bottom, hold the thermometer in place loosely with 2 fingers for about a minute or till you hear the beep.

• Withdraw the thermometer and check the digital reading. If a disposable plastic sheeth has been used, it should be discarded.

• A temperature of 100.4 degrees Fahrenheit (38 degree Celsius) or higher, measured rectally constitutes fever.

ORAL METHOD

It is the usual method recommended in children beyond the age of four years, provided the child is co0perative and capable of understanding instructions. Though it is not as accurate as the rectal method, it is accurate enough for substituting it in older children because of the convenience of use.

Steps in taking temperature by Oral Method

• Clean and rinse the tip of thermometer. Make sure that last readings are deleted.

• Carefully instruct the child not to chew it, not to speak while it is in mouth and to hold the thermometer by her lips. Ask her to lift the tongue up.

• Insert the thermometer tip in the mouth of the child, place it below the tongue and ask her to hold it with her lips. Wait for a minute or till there is the regular beep.

• Take it out and note the reading.

• A temperature of 99.5 degrees Fahrenheit (37.5 degree Celsius) measured orally is generally considered as fever by most paediatricians.

AXILLARY or ARMPIT METHOD

Between the age of 3 months and up to 4 years, and sometimes even in an older child that is either not fully cooperative or not capable of understanding instructions, temperature can be taken by this method. It is somewhat less accurate, but may still provide the information we are looking for. In a very sick child, or an uncooperative child it may have to be used sometimes.

Steps in taking temperature by Armpit Method

• Clean and rinse the tip of thermometer. Make sure that last readings are deleted.

• Remove the shirt and undershirt of the child.

• The thermometer is placed in the armpit making sure that it is contact with body and not clothes. The arm is held close to chest and is allowed to remain there for a minute or till the beep.

• Temperature is taken after the beep.

• A temperature of 99 degrees Fahrenheit (37.2 degree Celsius) measured in the armpits (axilla) is generally considered as fever by most paediatricians.

TYMPANIC METHOD using EAR THERMOMETER

This is one of more recently introduced methods and is gradually becoming popular due to its convenience, though it not as accurate or reliable as the rectal or oral method. However, it could be a substitute of armpit method which is also not very accurate. It requires a specific tympanic or ear thermometer. It can be used only after the age of 3 months and preferably, only after one year because the smaller size of ear canal in young child may reduce their accuracy. The advantage is that it can be done very fast and frequent readings can be taken easily. A major disadvantage is potential interference by ear wax, which can lead to misleading results.

Steps in taking temperature by Tympanic Method

• Familiarise yourself with the manufacturer’s instructions carefully. Where a disposable probe tip is provided, a new one should be used each time in accordance with the manufacturer’s instructions.

• Gently pull back the earlobe to straighten the ear canal, and insert the probe or the tip.

• Squeeze and hold down the button for one second. Remove the thermometer and read the temperature.

• Where more accurate readings are necessary, it may be preferable to follow it or confirm it with rectal or oral method.

TEMPORAL or FOREHEAD METHOD using FOREHEAD THERMOMETER

This is another more recent method, which is also not considered as accurate or reliable as the rectal or oral method, but makes available one more option. Because of its convenience, it may be preferable when frequent readings are required to monitor the child's temperature, or for screening of temperature in a group of children. Its advantage lies in its simple non-invasive use that allows measuring temperature without disturbing even a sleeping child.

Steps in taking temperature by Forehead Method

• Familiarise yourself with the manufacturer’s instructions carefully. Where a disposable probe tip is provided, a new one should be used each time in accordance with the manufacturer’s instructions.

• Following the instructions, the tip of the temporal thermometer or the designated part for scanning is placed over the forehead of the child, where temperature is scanned and electronically judged against the local temperature and other factors to give you a reading.

• Squeeze and hold down the button for one second. Remove the thermometer and read the temperature.

• Where more accurate readings are necessary, it may be preferable to follow it or confirm it with rectal or oral method.

How to Choose the Method

For a child less than 3 years, use the rectal method if accurate temperature reading is desired, for example when you need to decide as to whether to consult the doctor or not. Other methods that are less accurate and less troublesome are the ear method, armpit method and the forehead method.

For a child between 3 months to 4 years, rectal method is preferable for accuracy. Armpit, ear or forehead method may do when accuracy is not that important.

For a child over 4 years, oral method is preferable. Other methods like armpit or forehead method may have to be resorted if child is uncooperative or frequent readings need to be taken.

For the purpose of monitoring temperature during illness, it is better to use the same method consistently.

Precautions

Never take temperature immediately after the child has had a bath or sponging. Do not use the armpit method if the child is profusely sweating. Oral method should not be used within 20 minutes of having food or drinks.

Assessing the Temperature & Follow up Actions

It is useful to remember that fever is only a symptom and a not a disease in itself. Infections and allergies which are the common cause of fever are a part of growing up and development of immunity. Every time the child has fever may not be a case to panic, but certain conditions should always be referred to the physician.

Fever in a child less than 3 months should always be referred to a medical expert, and such consultation should not be delayed beyond 24 hours.

Fever associated with cough, yellow or green nasal discharge, diarrhoea or inability to feed should always be referred to a medical expert at the earliest, in particular if there are any signs of altered consciousness, high irritability, jaundice or breathing irregularity.

When in doubt, having an expert opinion will reassure you and help you avoid unending anxiety. Thus, if you are not sure and the night is approaching, it may be preferable and more convenient to consult the medical expert of your choice now rather than wait till midnight, panic and opt for less preferred choices.