A fever, is a distinct rise in a person’s body temperature that may be caused due to a bacterial, viral, fungal infection or through injury or disease. It is important to note however that not every incident of elevated body temperature classifies as fever temperature. On average a healthy person’s body temperature would be 37 degrees Celsius, but a range of temperatures between 36.1 C and 37.2 C also classify as normal body temperature. Fever is not considered medically significant until the body temperature is above 38 C, which is the temperature considered to be a fever temperature by medical professionals. Anything above normal but below 38 C is considered a low-grade fever. A low grade fever can serve as the body’s natural defense against bacteria and viruses, which is why a low grade fever temperature is often left untreated by medication.
The temperature in our bodies is usually controlled by the part of the brain called the hypothalamus which maintains normal temperature through heating mechanisms, such as shivering and increased metabolism, and cooling mechanisms, such as sweating and dilating (opening) blood vessels close to the skin.
The body temperature rises to a fever temperature when the body’s immune response is triggered by pyrogens (fever-producing substances). Some examples of fever temperature causing external pyrogens include:
Pyrogens function by causing the hypothalamus to increase the temperature set point. In response, our body begins to shiver; our blood vessels constrict (come close); we get under the covers in an attempt to reach the new temperature that is higher than our baseline. However, other pyrogens can be produced by the body, usually in response to inflammation; and these are referred to as cytokines.
One of the primary ways to deal with a patient with a fever temperature is to ensure that they are comfortable and well hydrated, and in a sterile environment. It is only if the fever temperature rises to 40 C or the patient starts to exhibit other symptoms such as vomiting, nausea or diarrhea that they should be taken in to see a specialist.