Low-grade fever
A fever is an abnormal increase in body temperature. This often occurs during the immune system’s reaction to a foreign substance in the body, such as bacteria or viruses. Infection with norovirus usually triggers a low-grade fever [10] that may persist throughout the infection.
Fevers may also have unknown causes or appear as symptoms of other chronic illnesses. If you have a persistent low-grade fever but do not have other norovirus symptoms, especially vomiting and diarrhea, you may be suffering from something else.