Characteristics of fever

How to deal with fever

What is fever?

Fever is a situation in which body temperature is higher than 37.8º C, when measured at any point outside the body, and over 38º C when measured via rectum.

Why does body temperature change?

The human body temperature can vary according to different factors such as:

  • By the time of the day (it increases in the afternoon and decreases in the morning)
  • Sex (during menstruation women can have up to a degree higher),
  • Physical activity
  • The outdoor temperature and humidity
  • Emotions
  • Disease

How long can fever last?

Patient suffering from fever

The duration of fever is variable and it is determined by many aspects that have to do with the patient’s age and type of infection or disease.

How is fever measured?

Thermometers are used to measure fever.

The most used is the glass thermometer which is usually placed in the mouth to make the measurement.

Some patients, especially children, prefer to take the temperature under the arm.

For young children there are special thermometers to measure the rectal temperature.

There are other electronic thermometers that can measure fever in the ear.

Symptoms of fever

Body temperature is regulated by the hypothalamus (a part of the brain that regulate many vegetative functions of our body) which is the one with the option to increase or decrease. To make these changes, our body has three regulatory mechanisms:

  • Blood circulation: The blood that circulates in the external capillaries cools down; the one that penetrates in the heart, warms up.
  • Metabolism: an increased metabolism produces heat
  • Muscles: tremors or muscle spasms produce heat
  • Sweating: Sweat draws heat as it evaporates and cools the body.

What are the phases of fever?

Patient suffering from fever
Having tremors is the main symptom we are in the first phase of fever

Fever takes place in three different fases:

  • First phase of fever: When our body sends blood from outside to inside, the body cools, which causes tremors. During this phase we are cold, we feel dizzy and our hunger decreases. (This is known as the first phase of fever)
  • Second phase of fever: The hypothalamus detects the need to increase body temperature, so it sends more blood to the outside heat, while producing heatgenerating muscle tremors. The body’s metabolism by eating more stored energy increases. This is done to increase body heat.
  • Third phase of fever: When you need to cool, sweating occurs. The sweat evaporates and carries heat, which reduces body temperature.

Function of fever

Fever is a response to infections caused by microorganisms. The functions of fever would be the following:

  • Creating a body temperature not suitable for the growth of bacteria and viruses. The organisms are adapted to live at a temperature above 37º C. Increasing the temperature the body helps inhibit their growth.
  • Creating a more suitable temperature for the development of antibodies. White blood cells increase with increasing temperature.
  • Increasing the pumping of blood to the area of infection thereby increasing white blood cells that will kill microorganisms.

It it dangerous to have fever?

Fever itself is not bad or dangerous but it is personally unpleasant. Fever actually is a support for the body to fight disease.

Usually fever does not usually exceed 40.5º C and rarely gets above 41º C, which would be dangerous.

The therapeutic function of fever has been so recognized that sometimes even artificial fever has been used to treat diseases such as arthritis.

A mild fever is appropriate and should not be treated immediately unless we find it very annoying.

When to consult the doctor in case of fever?

young baby
Babies should be rapidly attended in case of fever

It is generally considered that you should consult a doctor in the following situations:

  • For babies up to 2 months, when the rectal temperature is 38º C or higher.
  • In infants over 2 months when the rectal temperature is 38.8º C or higher.
  • For babies from 3 to 6 months when the temperature is 38.3º C or higher.
  • For babies from six months to a year when the temperature is 39.4º C or more.
  • In infants when, along with the fever, irritability or constant crying appears.
  • In infants and children up to two years when the fever lasts more than two days
  • In infants and children up to two years when, along with the fever, symptoms of lethargy or numbness take place.
  • In adults when it is higher than 40º C.
  • Any person, when the fever does not go away with conventional treatments home after 3 days of application. (We should not forget that in addition to infections, fever may respond to other factors such as tumors, poisoning, diseases of the immune system , etc.).
  • Where, in addition to fever, other symptoms: severe pain, headache, pain or stiffness in the back of the neck to bend the head forward, continuous vomiting, difficulty breathing, unusual sensitivity to light, rashes skin, painful urination, abdominal pain, inability to move a member, mental confusion or irritability, a symptom not explained.
  • Where, in addition to fever, ear pain, sore throat or neck pain appears.

Causes of fever

The main causes of fever are:

How to deal with fever at home

patient in bed
Staying in bed is necessary in case of serious fever

If you have fever or your are taking care for any sick with fever, we should consider the following tips:

  • Fever should be cured by resting at home.
  • Do not “over wrap” the patient. It is best fresh clothing that absorbs moisture. Cotton or linen sheets are better than fiber because they absorb more sweat. The patient’s bed should also have fresh linen. Pajamas should be lightweight and breathable.
  • The room should not be too hot
  • The forehead or chest of the patient can be wet with a damp cloth or sponge, with warm water. Also you can apply some ice under the armpits, crotches when temperature is high. You can also take a warm bath (never do it with cold water. Cold water makes you shiver what produces a temperature rise) Do not apply this medication to the patient when his/her temperature drops.
  • Do not use alcohol to cool the sick. Alcohol produces chills and it is absorbed through the skin, which is very dangerous especially in children.
  • It is important to provide plenty of fluids (water or juice) (You should not take stimulants like coffee, tea or cola, as these make you urinate too much, leading to a too high water loss, which together with the natural sweating that fever produces, can lead to dehydration).
  • Do not give aspirin or products with acetylsalicylic acid to children !!!

punto rojo More information on fever and its natural treatment.

Written by Editorial Botanical-online team in charge of content writing

15 April, 2020

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Botanical-online is an informative page that describes, among other topics, the traditional uses of plants from a therapeutic point of view. Their descriptions do not replace professional advice. Botanical-online is not responsible for self-medication and recommends consulting with the physician.