The level of temperature rise. What does the magnitude of fever mean?
Is high fever more severe or dangerous than moderate fever? It is clear that the physiological disorders associated with fever are roughly proportional to the degree of increase in body temperature, and the risk of developing complications, such as dehydration or febrile seizures, depends on the magnitude of the fever.
It is also obvious that there is a physiological upper limit of fever — a threshold temperature or a “safety valve” (about 41.1–41.7 ° C), upon reaching which the center of perspiration is activated and other heat transfer mechanisms are activated, preventing a further increase in temperature.
Body temperature above these figures, as a rule, is observed in thermal diseases, diseases of the central nervous system or when they are combined with infection. Such hyperpyrexia is rarely encountered with simple infections or other diseases. McCarthy showed that only 0.05% of the 210,000 admissions of children to the emergency room were associated with a temperature of 41.1 ° C or higher.
The next question is whether it is possible to reliably judge the severity of the underlying disease by the magnitude of fever. For example, what temperature is more dangerous – 41 ° С or 40 ° С? Does a child with a temperature of 40 ° C require more attention than a child with a temperature of 39 ° C? These questions with some reservations can be answered in the affirmative.
Carefully collected history and physical examination of a suddenly ill child with high fever, as a rule, can detect signs of a specific disease or an infection. Although, as a rule, the physician’s attention must first be directed to the treatment of the underlying disease, the severity of the fever remains a factor that must be taken into account when prescribing both symptomatic and specific treatment.
When the cause of the fever is unclear, the term “fever without local symptoms” is used, which will be discussed in a separate article on our website.