Fever wipes out one’s sins and rids his body from dead substances and germs. It is a blessing in disguise.

The Prophet sallallaahu ‘alayhi wa sallam (may Allaah exalt his mention) said:

“When a believer gets sick or feverish, it is like metal when put on fire, the bad is gone and the good remains.”
[Al-Bayhaqi]
He sallallaahu ‘alayhi wa sallam (may Allaah exalt his mention) also describes the intensity of fever by saying:

“Fever is coal from hell, get rid of it by using cold water.”
[Ibn Maajah]
The Prophet sallallaahu ‘alayhi wa sallam (may Allaah exalt his mention) forbade the cursing of fever by saying:

“Do not curse a fever because it abolishes sins like fire abolishes dirt from iron.”
[Ibn Maajah]
A bacterial or viral infection usually raises the temperature of a person, antibiotics are useless with viral infections, such as the influenza and the common cold, although the patient might sweat and have a very high fever.

Then what is the cure?

The Prophet sallallaahu ‘alayhi wa sallam (may Allaah exalt his mention) tells us to reduce the fever with water. The same is still applied today. Putting cold pads on a patient’s forehead is still used in a lot of hospitals and by doctors even though fever reducing medicines are abundant, like aspirin, paracetamol (or acetaminophen, which is the active ingredient in Tylenol) and others.

Using water to reduce fevers is not limited to using cold pads. Drinking a lot of fluids is also helpful. This is also understood from the wordings of the Prophetic narration: “cool it with water.” Water is either what the patient drinks, what is given intravenously or what the patient puts on his face or body to cool the fever.

We have seen a lot of patients where fever reducing medicines (antipyretics) were not effective with their rising fever. At the same time, cold water had an immediate effect. That’s why pediatricians advise parents to take a child’s clothes off and give a lot of fluids if a fever occurs. An antipyretic might also be give like paracetamol. Aspirin has been banned for children under 12 years of age.

What is fever?

Fever occurs when the body temperature rises above normal (37 C). There is an area in the brain (an area that lies over the pituitary gland in the front of the head) which is a temperature regulator.

When a germ enters the body, it starts secreting toxins. Toxins affect the temperature regulator causing its temperature to rise. The substances that cause this rise in temperature are called pyrogens. Pyrogens are caused not only by germs but also by the ruined tissues in the body after being affected with germs.

When the temperature rises in the temperature regulator, the rest of the body has to comply. It increases its temperature in response. Soon, the whole body feels feverish and the patient’s temperature rises. This explains the saying of the Prophet sallallaahu ‘alayhi wa sallam (may Allaah exalt his mention) when he described the believers in their kindness and affections like the body. If a part of it suffers from a germ or a virus, like inflammation in the respiratory pathways or inflammation of the urinary tracts and others, all of the body suffers from fever and restlessness.

Yes the whole body suffers. The whole body has a rise in temperature and not only where it is affected. When the inflammation worsens, the germs increase and consequently ruin the tissues. The germs and the pyrogens will find the body’s defense system ready to attack and eat the by-products of the germs and rid the body of them. While doing this, it releases to the body fluids a substance called leukocyte pyrogens or endogenous. Therefore the fever remains while the body is cleansing itself from the by-products.

Didn’t the Prophet sallallaahu ‘alayhi wa sallam (may Allaah exalt his mention) say, when a man cursed the fever:

“Don’t curse it because it abolishes sins like fire abolishes dirt from iron.”
It is a cleansing of our sins, a cleansing of dead substances such as dead tissue and the by-products of the germs, like fire cleans the dirt from iron.

The famous book on physiology by Guyton, 1992 edition, stated that an amount equal to one over 10 billionth of a gram of endogenous is enough for a fever to occur.

Such a small amount of a substance secreted in the body due to a very small germ or a virus is enough to transfer a person form being healthy, to becoming sick, feverish and bed ridden.

Imaam Ibn Al-Qayyim may Allaah have mercy upon him said: “I remember once, when I was feverish, a poet cursing the fever, saying.

The sin purifier has visited and left.

How evil it is when visiting and when

leaving

She asked while getting ready to leave What

do you want?

I replied, to never come again.

I said, shame on him, he cursed what the Prophet sallallaahu `alayhi wa sallam ( may Allaah exalt his mention ) forbade to be cursed. If he had said:

The severe-sin cleanser has visited.

Greetings to it while visiting and while

leaving

She asked while getting ready to leave What

do you want?

I replied, to not leave.

It would have been better for him and it still would have left.”

Recent scientific studies have shown that this leukocyte pyrogens cause fever by making a substance called prostaglandin in the local glands in the area of the hypothalamus. When the growth of this kind of prostaglandin is inhibited, by using medicines, the fever is reduced. This explains how aspirin reduces fever. It inhibits the growth of prostaglandin and prevents its making.

The Prophet, sallallahu ‘alayhe wa sallam, said:

“For every ailment, there is a cure. If the cure reaches the ailment, it is cured by the will of Allaah.”
[Muslim]
That explains the known phenomena that aspirin does not reduce the temperature of a normal person who is not feverish. That is because he does not have these endogenous in his body to work on the hypothalamus.

How do chills occur and why?

The temperature level in the temperature regulator rises suddenly form its normal level to a higher level, due to damage in the tissues, due to the release of temperature generating substances or due to dehydration. When this happens, the body temperature rises within a few hours to attain the new temperature.

During this period, the patient shivers and feels cold, even though the body temperature is high, because blood vessels in the skin contract. The chills remain until the body temperature reaches the new level set by the temperature regulator.

When the body temperature reaches that level, the chills stop and the patient feels neither warm nor cold. As long as the infection continues and the reason for the rise in temperature continues, the body temperature remains at this new level until Allaah permits recovery.

(source: http://abdurrahman.org/health/fever.html)