A 5-month-old baby’s 37 degrees is not considered fever. 5-month-old baby’s normal body temperature: anal temperature is 36.5 degrees-37.5 degrees; axillary temperature is 36 degrees-37 degrees; sublingual temperature is usually 0.2 degrees-0.5 degrees higher than axillary temperature. Fever is defined as an anal temperature ≥38 degrees or an axillary temperature ≥37.5 degrees, and a fluctuation of more than 1 degree within 1 day is called fever. The degree of fever is determined by the axillary temperature: hypothermia is defined as a temperature <38 degrees; moderate fever is defined as a temperature between 38 degrees and 39 degrees; high fever is defined as a temperature between 39 degrees and 41 degrees; and extreme fever is defined as a temperature >41 degrees. It should be noted that the degree of fever does not necessarily reflect the severity of the disease. For example, colds can cause fever, and newborns or infirm children with severe infections often have a low or moderate fever, or even a temperature that does not rise.