How to Check Your Child's Temperature for a Fever

Does your child have a fever?

Father with sick children calling doctor
Tim Hawley/Digital Vision/Getty Images

Among all of the symptoms that their kids may have, such as a cough, sore throat, and vomiting, etc., fever seems to be the one that parents often seem to worry about the most.

Is their child's fever too high?  What is the best way to check their child's temperature? Why do they even have a fever?

Does Your Child Have A Fever?

One of the first questions to consider about fever is whether your child even has a fever.

Does he feel warm or hot? Surprisingly, you may be right about eighty percent of the time the time if you rely on your child feeling warm to determine if he has a fever. Another study has found that mothers who said thought that their kids had a fever without using a thermometer, or had a subjective fever, were only right about half the time, though.

So if using the old hand on the forehead trick isn't to be trusted, and you aren't supposed to use mercury thermometers anymore, what are you supposed to do?​

Since there are now so many different methods of taking a child's temperature, your best bet is finding out if your pediatrician has a preferred method for you to take your child's temperature. Although one method is not necessarily better than another, it may be that your pediatrician really prefers that you use an ear thermometer, temporal thermometer, or a mercury free oral thermometer.

High Fevers

What is a high fever? It depends on who you ask...

In general, parents worry much more about fever than most pediatricians do. The phrase 'fever phobia' has even been used to describe how much some parents worry about their child's fever.

In addition to understanding that fever is usually just another symptom, like a runny nose or a cough, it can help to combat fever phobia by understanding what normal temperatures you can expect your child to have when he is sick.

In general, you should usually call your pediatrician if he has a temperature at or above:

  • 100.4 degrees Fahrenheit and he is under three months old
  • 101 degrees Fahrenheit and he is between three and six months old
  • 103 degrees Fahrenheit and he is over six months old

However, just as important as your child's temperature, also consider this other advice from the American Academy of Pediatrics:

  • In most cases, your decision to call your pediatrician also will depend upon associated symptoms such as a sore throat, earache, or a cough.
  • If a high fever persists for more than twenty-four hours, however, it is best to call even if there are no other complaints or findings.

Which Thermometer is Best?

Although temporal thermometers, which you simply scan across your child's forehead, and ear thermometers are becoming very popular among parents because they are fast and easy to use, they can be expensive. More simple, mercury free, digital thermometers are much less expensive but do take longer to get a reading, which can be a problem if you have a fussy child who won't stay still for 1 to 3 minutes.

Keep in mind that there are pros and cons to most thermometers, including that:

  • Mercury free rectal thermometers are the most accurate, but they can be uncomfortable, so should usually be reserved for infants under about 3 months old, although some people continue to use them until their child is 3 years old.
  • Mercury free oral thermometers are also accurate, but they are usually reserved for older children since they must usually be held in the mouth for at least a minute or so. Most can also be used under the arm, as an axillary thermometer.
  • Ear thermometers are fast and easy to use, but they must be placed in the ear properly, can be expensive, and excessive ear wax may interfere with the reading.
  • Temporal thermometers are becoming increasing popular, since they are fast and easy to use, but they can still be expensive.

And remember that you usually shouldn't use an ear thermometer or under the arm (axillary) thermometer in younger infants, since many people don't think that they are very accurate at that age.

What To Know About Checking Your Child's Temperature

Other things to know about checking your child's temperature include that:

  • Instead of adding or subtracting a degree when you report your child's temperature to your pediatrician, simply report the temperature and how you took it. Rectal temperatures are usually about 1 degree higher than oral temperatures and 1 1/2 degrees higher than axillary temperatures, but since you don't have to add a degree with ear or temporal thermometers, talking about adding or subtracting a degree can be confusing.
  • Most people consider a fever in younger children to be a temperature at or above 100.4 degrees Fahrenheit, so a temperature of 100 in a 1-year-old is usually normal and not a low-grade fever
  • You usually don't need to wake a sleeping child to check their temperature at night or give them a fever reducer if they are sleeping comfortably.
  • Unless your child has heat stroke ​like if you left him in a hot car, it is unlikely that your child's temperature will get high enough to be dangerous.
  • When using temporal thermometers or ear thermometer, it can sometimes be helpful to take 2 or 3 readings and average them together.
  • If you want to test your thermometer's accuracy, consider bringing it to your next visit to your pediatrician and compare the reading it gives against the one that your pediatrician uses.

Most importantly, remember that your child's temperature doesn't usually tell you how sick your child is or even what they might have since he could have a high fever with a cold, the flu, strep throat, or many conditions that have nothing to do with an infection.


Banco L. Ability of mothers to subjectively assess the presence of fever in their children. Am J Dis Child 01-OCT-1984; 138(10): 976-8

Hooker EA. Subjective assessment of fever by parents: comparison with measurement by noncontact tympanic thermometer and calibrated rectal glass mercury thermometer. Ann Emerg Med 01-SEP-1996; 28(3): 313-7

Your Baby's First Year. The American Academy of Pediatrics. Bantam; 2010.