Low fever has been 37.8 ℃. It is recommended to go to a regular hospital in time, improve relevant examinations, clarify the cause of low fever, and give corresponding treatment. At present, the causes of fever are mainly divided into infectious factors and non infectious factors. Infectious factors commonly include bacteria, viruses, fungi, mycoplasma, chlamydia, Rickettsia, etc. Low fever can be seen in the lungs, upper respiratory tract, urinary system, etc. Non infectious factors that cause low fever mainly include blood system diseases, malignant tumors, rheumatic and immune diseases. Since there are many reasons for low fever, it is recommended to go to a regular hospital in time.