This article is about the medical condition. There is not a pyrexia of unknown origin pdf agreed-upon upper limit for normal temperature with sources using values between 37. This results in greater heat production and efforts to conserve heat. This is more common in young children.
Treatment to reduce fever is generally not required. Treatment of associated pain and inflammation, however, may be useful and help a person rest. Measures such as putting a cool damp cloth on the forehead and having a slightly warm bath are not useful and may simply make a person more uncomfortable. While fever is a useful defense mechanism, treating fever does not appear to worsen outcomes.
Fever is viewed with greater concern by parents and healthcare professionals than it usually deserves, a phenomenon known as fever phobia. Note: The difference between fever and hyperthermia is the underlying mechanism. Different sources have different cut-offs for fever, hyperthermia and hyperpyrexia. Central temperatures, such as rectal temperatures, are more accurate than peripheral temperatures. Normal body temperatures vary depending on many factors, including age, sex, time of day, ambient temperature, activity level, and more. A raised temperature is not always a fever. For example, the temperature of a healthy person rises when he or she exercises, but this is not considered a fever, as the set-point is normal.
On the other hand, a “normal” temperature may be a fever, if it is unusually high for that person. Drops due to fever-reducing drugs are excluded. However, there is some debate as to whether this pattern truly exists. Infections are the most common cause of fevers, but as the temperature rises other causes become more common. Immediate aggressive cooling to less than 38.
As can be seen, hyperthermia can be conceptualized as an increase above the thermoregulatory set point. Characterized in the center: Normal body temperature is shown in green, while the hypothermic temperature is shown in blue. As can be seen, hypothermia can be conceptualized as a decrease below the thermoregulatory set point. Characterized on the right: Normal body temperature is shown in green. It reads “New Normal” because the thermoregulatory set point has risen. PGE2 then in turn acts on the hypothalamus, which generates a systemic response back to the rest of the body, causing heat-creating effects to match a new temperature level. When the set point is raised, the body increases its temperature through both active generation of heat and retention of heat.
A pyrogen is a substance that induces fever. In other words, exogenous factors cause release of endogenous factors, which, in turn, activate the arachidonic acid pathway. These enzymes ultimately mediate the synthesis and release of PGE2. PGE2 is the ultimate mediator of the febrile response. The set point temperature of the body will remain elevated until PGE2 is no longer present. There are arguments for and against the usefulness of fever, and the issue is controversial.
Studies suggest reduced mortality in bacterial infections when fever was present. In theory, fever can aid in host defense. Fever should not necessarily be treated. Most people recover without specific medical attention. Although it is unpleasant, fever rarely rises to a dangerous level even if untreated. Some limited evidence supports sponging or bathing feverish children with tepid water.