Fever after vaccination, oral temperature of 37.3-38℃ belongs to low fever, which can be gradually recovered by giving ice bags to cool down, opening windows and ventilation, and drinking more water in general. If the fever exceeds 38℃ in adults and 38.5℃ in infants and children, it is recommended to go to the hospital for consultation and treatment under the guidance of the doctor after clarifying the cause: I. General treatment: Hepatitis B vaccine, pneumonia vaccine, pepto-bismol, influenza vaccine and new crown vaccine can cause slight fever, mainly due to the immune reaction of the body after vaccination, which stimulates the temperature center and causes fever, usually for several hours or 1-2 days The fever usually resolves itself in a few hours or 1-2 days. If the fever is only low, drink more warm water or cool down by physical means, such as giving cold towels, ice packs or wiping the whole body with warm water. The temperature can be measured at intervals of about 4 hours to observe changes in body temperature, and the fever can generally be gradually reduced. Second, drug treatment: If the patient measured the oral temperature exceeds 38 ℃, or even rise to 39-40 ℃, should immediately seek medical attention. On the way to the hospital can try ice bags, ice towels and other physical cooling. The principle is to promote heat dissipation by reducing the excitability of the thermoregulatory center, dilating blood vessels and stimulating sweating to achieve the purpose of cooling. Common drugs include ibuprofen and acetaminophen, which can be tolerated by both adults and children. Meanwhile, indomethacin, meloxicam, naproxen and other drugs can also be applied to reduce fever in adults. Third, other treatment: There are also patients with fever that may not be caused by vaccination, then it is necessary to improve the examination and clarify the cause. In addition to cooling the fever, treatment of the primary disease is also required. Antibacterial agents such as levofloxacin, roxithromycin and cephalosporin can be applied to fever caused by bacterial infection, and antiviral drugs such as ribavirin, acyclovir and ganciclovir can be applied to fever caused by viral infection.