When a 5-month-old baby has a fever for the first time, he or she can be cooled down by physical cooling or antipyretic medication, depending on the specific temperature. In addition, it is also necessary to promptly find the cause of fever and give targeted treatment. 5-month-old infants with first fever, if the temperature is below 38.5 ℃, you can use warm water to wipe the armpits, groin and other parts of the physical cooling, in addition to pay attention to avoiding cold, etc.. If the temperature of a 5-month-old baby is over 38.5℃, then in addition to physical cooling, some antipyretic drugs, such as acetaminophen, can be used under the guidance of a doctor. In addition, according to the cause of fever, targeted treatment. If it is caused by bacterial infection, you can use antibacterial drugs such as cephalosporin to treat it. There are many possible causes of fever in 5-month-old babies, and it is recommended to go to the hospital in time and clarify the cause of the disease early for standardized treatment to reduce the adverse effects of the disease.