A high fever, or simply a small degree above normal (namely 37,5 ° C), each human being meets relatively frequently in his life, from the youngest age (infants) to the elderly. How to define the feverish state?

To be feverish is to have a fever. Fever is an increase in body temperature above normal values. It is having a core temperature (as opposed to skin temperature) above 38,3 ° C, in the absence of physical activity and being normally covered.

At best, the temperature should be measured away from meals and after 20 minutes of rest.

The use of a thermometer is essential, rectally, orally, or in the armpit. For these last two measurement sites, 0,5 ° C is added to the value read on the thermometer. The rectal route is no longer recommended because of the risk of damaging the rectum when taking a temperature.

The use of a tympanic thermometer is possible but an earplug can falsify the results. The electronic thermometer used on the forehead or temple is unreliable.

A distinction is made between acute fevers (dating less than 5 days) which are most often infectious and chronic fevers (over 20 days) which have a non-infectious origin in half of the cases.

Fever is very often accompanied by other symptoms:

• great fatigue;
• chills;
• lack of appetite ;
• profuse sweating.

Fever is not in itself a bad thing, since it is the body’s defense mechanism against infections, whether bacterial or viral.

In the presence of germs or viruses, the immune system detects “foreign bodies” called antigens. The detection of these antigens will cause a cascade of biochemical reactions and the release in the blood of cytokines which will cause fever by setting the “thermostat” of the human body on hot. This biological thermostat is located in the hypothalamus.

From a utilitarian perspective, the increase in body temperature will allow the chemical reactions involved in the body’s defense to take place more quickly. It is wrongly believed that the rise in temperature serves to destroy foreign bodies, but this has never been shown. Further studies would show that fever helps immune cells move faster to the site of infection. Thus, fever improves the efficiency of the immune system.

There are other causes of fever:

• inflammations;
• heat stroke;
• hyperthyroidism;
• a reaction to a vaccine;
• venous thrombosis;
• a trauma.

Usually, the fever is not serious on its own. Counterintuitively, you should know that the intensity of the fever is not related to the severity of the infection. Thus, one can have a high fever (during a flu, for example), and a mild infection which will heal quickly.

Conversely, some people (elderly subjects, alcoholism) can have very severe infections with very little or no fever at all.

In conclusion, there is no correlation between the extent of fever and the severity of the disease or infection.

A fever can be worrying when it rises above 40 ° C and lasts more than 3 days. Otherwise, it does not require special treatment, since its presence shows that the immune system is in action against the infection in place in the body.

Of course, the elderly, young and very young children, pregnant women, and patients with chronic illnesses must consult quickly in the event of fever, even if not prolonged, and especially if it is accompanied by other symptoms:

• vomiting;
• diarrhea;
• difficulty in breathing;
• partial unconsciousness;
• convulsions ;
• faintness ;
• severe pain in the stomach or chest.

In order to control the fever, the patient may, following the recommended dosages, take antipyretic drugs, which can bring down the fever, such as paracetamol, and nonsteroidal anti-inflammatory drugs. Aspirin is no longer recommended for fever. Be careful, however, to strictly adhere to the indicated dosages, possibly with advice from the pharmacist.

It is advisable to monitor the evolution of the fever, also to rest in a ventilated place, not too hot, not to cover oneself and to drink enough. Lukewarm water bath in children may be indicated. If symptoms worsen and accumulate, the patient should seek medical attention promptly.