Why Do We Get A Fever?

The normal core human body temperature of the healthy person is considered 98.6ºF and it hovers within the range of +/- 1 deg. F and small variations due to age, activity, time of the day, etc. are acceptable. The temperature recorded from different parts of the body like orally, vaginally; rectally show almost same with minor variance. The temperature of the skin, usually recorded under the armpits show slight lower readings.

When the core body temperature rises above 99.5ºF the body condition is called “fever”. Usually, when the body suffers from the attack of foreign infections like virus or bacteria, the temperature of the body rises to stimulate the immune system to fight the infection. It is also helpful in mitigating the growth of temperature-sensitive bacteria or virus which cannot survive the increased body temperature environment.

The hypothalamus, a small organ situated at the base of the human brain, is considered to be the thermostat of the human body and keeps the body temperature within the normal range, despite ambient environmental changes, so that its major organs can function properly. Whenever the immune system of the body perceives any threat from any part of the body, the tissues of the cells around the identified area release a biochemical substance called pyrogens. Many pathogens also produce pyrogens. When the floating pyrogens are detected by the hypothalamus through the blood stream, the hypothalamus directs the body to generate more heat which results in fever. Children are typically more prone to quick and frequent fevers due to an effect of pyrogens since the immune system of the body is relatively inexperienced in childhood.

Fevers or high body temperature signals presence of infection within the body and also is the result of the natural response of the body to spruce up it is the immune system to fight that infection. The elevated body temperature also supports the immune system to neutralize the harmful virus or bacteria present in the body. The higher body temperature does not allow the body to remain a receptive host to the harmful pathogens and impedes their multiplying capability within the body. Thus, all fevers are not bad and sometimes lowering the body temperature by taking the drug like Aspirin is not favorable since it hampers the body mechanism to get rid of the harmful bacteria.

However, when the body temperature rises above 104º F, medical or drug intervention is necessary to bring down the temperature. The body temperature above 104ºF is not good for the body since it interferes with proper functioning of other vital organs with lethal consequences. Seizures, infarctions, cellular stress, etc. are the potential problems which can occur when the body is suffering from prolonged and severe high fevers.

There are other causes of fever as well like fever due to heat stroke. Similarly, abuse of amphetamines or alcohol withdrawal also induces higher body temperature or fever. Many diseases like Tuberculosis, typhoid, malaria, etc. are accompanied by high fevers with characteristic trends and allied symptoms.