How is your body temperature regulated?

Our brain contains a part that serves as a thermostat, similar to the thermostat in your home. Normally, this thermostat is set at 37 degrees Celsius. If the body temperature drops below 37 degrees, the body will try to increase the temperature (the heating comes on). You will get goose bumps, start shivering and your metabolism will increase until the right temperature is reached again. If your body gets too hot, for example during hot weather or while exercising, the opposite happens and you will begin to sweat and your blood vessels will widen to get rid of as much heat as possible.

When does a person have a fever?

In the 19th century, a study was carried out in which the temperature of 25,000 healthy people was measured over an extended period of time. This is how we know that your temperature varies throughout the day, is typically higher in the evening than in the morning and that the average temperature varies from person to person and also depends on the day of the month.

A normal temperature is between 37 and 38 degrees Celsius.

A subfebrile temperature is in the range of 38 and 38.5 degrees

Fever is a temperature above 38.5 degrees (measured rectally)
Periodic fever = more than 3 episodes in 6 months
At least 7 days in between in which the patient recovers

Why do you develop a fever?

A fever is a normal response of the body to infection and/or tissue damage. When the immune system encounters a bacteria or virus (or damaged cell), the cells of the immune system will start to produce inflammatory proteins (cytokines). These cytokines trigger the production of prostaglandin. Prostaglandin causes the thermostat in your brain to be set to a higher temperature.  Your body will now try to heat up to this temperature (the heating comes on). That’s why you often start feeling cold and start shivering when you develop a fever. When you are recovering, the thermostat goes down and your body will try to cool itself by sweating, etc. (the heating is turned off briefly).

Fever has a purpose.

The body deliberately causes your temperature to rise when you have an infection.

Fever inhibits the growth of viruses and some types of bacteria. And it activates immune cells. Also, the faster heart rate and breathing allows more oxygen, nutrients and immune cells to be pumped around. In this way, the infection can be fought more effectively.  It is therefore not always necessary to treat the fever yourself (for instance with paracetamol or diclofenac). However, it is very important to find out what is causing the fever and, if necessary, to treat the cause of the fever.

In the long term, fever can have adverse effects. Fever affects the nervous system and can therefore lead to a decreased level of consciousness, delirium or, in children, febrile seizures. In addition, fever costs the body a lot of energy.

Certain children, such as newborn babies or children with an immune disorder, are extra vulnerable to infections. If these children develop a fever, a family doctor or hospital needs to be visited sooner.