Taking your child’s temperature

The best way to check your child’s temperature is with a digital thermometer. Digital probe thermometers are the most accurate. They measure temperature under the tongue or armpit and sometimes rectally. Ear thermometers and temporal artery thermometers are easy to use but can be inaccurate.

The average body temperature for children is about 37°C. If your child’s temperature is higher than 38°C, she probably has a fever.

Types of thermometers

It’s best to check your child’s temperature using a thermometer. Feeling your child’s skin temperature by putting your hand to his forehead isn’t a reliable way of diagnosing a fever.

Most modern thermometers are digital thermometers.

Digital probe thermometers
You can use a digital probe thermometer to take your child’s temperature in 3 main ways:

  • Orally (under the tongue):  you may use this methods for chldren older than 4 years. 

  • Axillary (under your child’s armpit): You may use this method for chidren aged 3 month to 4 years. It is less accurate than oral or rectal temperature. 

  • Rectal temperature.  this practice is not recommended by some experts since there’s a risk that the tip of the thermometer could damage the lining of the child’s rectum.  However this is the most accurate measurment and many expert believe that this is the best method for babies from birth to 3 months and may be also used for children aged 3 months to 4 years. 

 You can clean a thermometer using warm soapy water or an alcohol wipe.

Digital ear thermometers
Ear thermometers are quick and easy to use, but they can be  inaccurate.

Digital forehead or temporal artery thermometers
These are the easiest types of thermometers to use, They can be used even while a child is asleep but they can be inaccurate.

Other thermometers
Digital pacifier thermometers, fever strips and smartphone apps aren’t recommended because they’re not very accurate.

Mercury thermometers can poison a child if they break and they are not recommeded. 

Taking your child’s temperature

No matter what kind of thermometer you have, it’s important to carefully read the instructions that come with it before using it for the first time.

Here are more tips to help you take your child’s temperature accurately.

Oral temperatures
You take an oral temperature using a probe thermometer:

  • Wait five minutes after your child has had a hot or cold drink.
  • Place the thermometer well under one side of your child’s tongue.
  • Have your child hold it in place with her lips, not her teeth, and tell her to breathe through her nose.
  • Wait until the thermometer beeps and then check the digital display for the temperature reading.

Add 0.5°C to your child’s oral readings to estimate his true body temperature.

You can take oral temperatures in children over four years. It’s hard to take an oral temperature in children younger than this, because they can’t always co-operate with you.

Armpit temperatures
You take an armpit temperature using a probe thermometer:

  • Place the thermometer in your child’s armpit.
  • Close your child’s arm over the thermometer, holding his elbow against his body.
  • Wait until the thermometer beeps and then check the digital display for the temperature reading.

Taking your child’s temperature under the armpit is usually the easiest way to do it, especially in young children. Unfortunately, it’s also less accurate than an oral temperature reading.

Add  1°C to your child’s armpit readings to estimate her true body temperature.

Rectal temperature: If you check rectal temperature, lubricate the tip of the thermometer with petroleum jelly. Lay your baby or child on her back, lift  her thighs, and insert the lubricated thermometer 1/2 to 1 inch (1.3 to 2.5 centimeters) into the rectum. Alternatively, you can place your child on the belly on your lap or other firm surface. If you put your child belly down, put your hand against his or her lower back to hold the child in place. Never try to force a rectal thermometer past any resistance. Hold the thermometer in place until the thermometer signals that it's done. Remove the thermometer and read the number.

When to see a doctor about fever and high temperature

Babies under three months who have a fever should be taken to a hospital emergency department straight away. This is because it’s harder to tell whether they have a serious underlying illness.

In children aged 3-12 months, fever might be a sign of a more significant illness, so seek medical advice from your doctor preferably within the same day.

In children over 12 months, go to a hospital emergency department or call an ambulance straight away if your child has a fever plus other signs of serious illness like severe pain, drowsiness, pale or blue skin, dehydration, troubled breathing, a stiff neck, persistent vomiting and reduced responsiveness.

If your child’s temperature doesn’t improve within 48 hours, see your doctor.

You can take your child’s temperature as often as you need to – for example, every 3-4 hours. But the most important thing is to watch your child for signs of serious illness.