Fever is the increase in body temperature above the normal level.
Fever is the most common symptom of many diseases and usually the first thing parents realize. Today, after many clinical studies mainly in animals, we have the knowledge.

We know, for example, that the normal body temperature of each organism is regulated through an extremely complex mechanism.
In superior mammals, and hence in humans, the centre of this mechanism lies in a part of the brain called the hypothalamus. This centre acts as a “thermostat” that can regulate the temperature at certain levels. Under regular conditions the thermostat regulates the external temperature of the human body, i.e. the temperature of the skin (e.g. the underarm) at about 36.5-37.2oC. In various pathological conditions, however (notably infections, either from viruses or bacteria) the thermostat “raises” the body temperature to a higher level (more than 38oC). In these situations we have a fever.

Over what temperature do we say that children have a fever?

Before answering this question, two issues have to be clarified.
A. Where is the measurement of temperature carried out from?
B. What is the normal temperature of the human body

A. The temperature is usually measured in the axilla (armpit), rectum or mouth with various thermometers, or less often on the skin with the use of various films. The latter, however, is not very reliable. Parents usually measure the temperature of older children under the armpit, while infants in the rectum.

B. As for all biological sizes of a human (height/weight), the body temperature is not a determined and exact number. Hence, it is not possible to say that the normal axillary temperature is 36.6°C as we can not say that the weight of a normal adult is 78 kg. The normal human body temperature measured under the armpit ranges from 36.2 °C to 37.2 °C and depends on multiple factors.

While the body temperature is low in the early morning hours (4-5 am), it rises in the afternoon, especially regarding children after intense exercise (e.g., playing).

All of the above allows us to state that a child has a fever when his rectal temperature is higher than 37.8 °C or axillary temperature is higher than 37.3 °C. It should also be noted that, in accordance with official terminology, high fever is considered as such when the temperature exceeds 40.5 °C.

How justified is the fear of fever?

The following considerations will help provide an answer to this question.

1. It has been proven today that a fever is a very useful and revealing symptom. We can know that many germs and viruses significantly reduce the rate of multiplication of the viruses at high temperatures (e.g., 39 °C). Furthermore, a high temperature mobilizes a series of the body’s defence mechanisms, so that it can “fight” germs or viruses more efficiently.

Therefore, the fever is an ally and not an enemy.

2. Fever is not a disease; it is a symptom (such as cough) that is due to many causes.
The most important of these (especially with children) are the various infections from bacteria or viruses. But fever can be a symptom of other diseases and also a reaction to drugs.

Therefore, is fever dangerous? The answer is simple and clear:

Fever by itself is not dangerous, but the cause for which the child has a fever can be.
If a child has fever because he has, for example, an ordinary infection, even high fever should not worry us. This of course means that the child with a fever should be examined by a paediatrician, so as to determine the cause of fever.

How to treat fever?

Fever is treated with the use of antipyretic drugs. Considering that a fever is a useful weapon for the body to fight infections, it would be wise to allow the person to have a fever. The fever, however, especially high fever, causes discomfort, restlessness, crying, etc. If a child presents fever symptoms, he should be administered antipyretics. In other words, fever is not treated because it is dangerous, but because it causes discomfort to the child. If your child is lively and playful, even if his temperature is at 39°C, it is not necessary to give him antipyretics. However, children with an axillary temperature (armpit) over 38,5 °C feel bad and are usually administered antipyretics drugs over this temperature.

Antipyretics exist in various forms (syrups, suppositories, drops etc.). Each of these forms contains a given amount of active substance. The dose of antipyretics should determined by the weight of the child, and for this reason parents should consult their paediatrician.