Should we always treat a fever?

Fever is one of the most common symptoms that parents report running in to see their doctors. In fact, it is estimated that half of emergency room visits in children internationally is because of fever.


It is important to remember that fever is not a disease, but rather the body’s response to an illness. Sometimes, that is a good thing, as it may, in fact, shorten the course of your child’s illness. It may also alert you to a more serious underlying problem. The question is: is fever always bad and should we always be treating it?


Our body temperature can vary with age, general health, the time of day and the activity level. According to the American Academy of Pediatrics, everyone’s temperature is more likely to be lower in the early morning and higher between later afternoon and early evening. Your child’s core temperature can vary as much as 1 to 1.5 degrees Fahrenheit throughout the day. The standard definition of fever is a rectal temperature of 38 degrees C (100.4 F) or higher.


While fever can occur in any age group, infants up to 6 months of age are in a group of their own and always require an assessment by their doctor. For babies in this age group, doctors must assess what the underlying cause is. In this age group, the kinds of bacteria and viral bugs that cause illness are different than older children. As well, these very young infants have an immune system that is not able to fight as efficiently as older children. For all other children, if a fever is ongoing past 72 hours, your child must be seen by the doctor.


When we or our child get a fever, our first response is to get the fever down. Now, however, there is indeed concern that our desire to get the temperature down may be the wrong thing to do. There is even concern that getting a temperature down may hinder the ability to fight what is causing the fever in the first place.


Fever is part of our body’s infection fighting strategy, if you will. It is useful to actually get rid of the agent that has led to the fever.


A fever starts as a response to an infection. The infection leads to the release of fever-causing agents that are called pyrogens. Research has shown that our fighter cells, called T lymphocytes, work better to fight infection when we have a fever. They work better under these hotter conditions. Research has also shown that fever has a direct effect on the bugs that are causing the infection. These microbes do not survive as well in the heat.


Studies recently reported in the British Medical Journal showed that for patients who were admitted to hospital, those with a fever on admission did better than those who presented without a fever.


However, lest we generalize this information to all people with fever, there are indeed times when a fever can be a bad thing. Certainly, the very young or patients with a head injury or stroke are groups where a fever is known to be harmful.


In other instances, doctors have come to the conclusion that we do overmedicate when we see a fever. There is the possibility for the average child with an infection that the fever is actually beneficial. If your child is uncomfortable with a fever, it might seem reasonable to treat, but for many children, it just is not necessary (with the exception of those under the age of 6 months who always require a complete assessment to know where the fever is coming from).

How do I take a temperature?


An oral thermometer doesn’t usually work in children younger than five, simply because it is too hard for them to hold the thermometer in place.


While the axillary method is usually reliable, if you are convinced your child has a temperature and this method does not confirm it, it might be best to repeat the measure with a different method. Like the mouth in young children, sometimes it is hard to hold the thermometer in place with the arm closed tightly around the thermometer. Under the age of 2, a rectal thermometer should be used.


Ear thermometers can be complicated to use and are not suggested for use in children under 2. Sometimes it is hard to get a seal in a young child’s ear with the probe and the temperature might be underestimated.


What is a normal temperature?


According to the Canadian Pediatric Society what is normal indeed will vary by the method that you have used. For example, a rectal temperature, can range from 36.6C  to 38 C (97.9 F to 100.4 F). Mouth readings on the other hand can yield normal between the range of 35.5C to 37.5C (95.9F – 99.5F).