Influenza A fever of 40 ℃ can be treated with general treatment, the use of antipyretic drugs and antiviral drugs. 1. General treatment: Influenza A fever patients should eat a light diet, drink plenty of water, pay attention to warmth, avoid catching cold, use warm water to wipe the forehead, armpits and other ways to physically lower the temperature. 2. Fever-reducing drugs: Acetaminophen, ibuprofen, indomethacin and other non-steroidal anti-inflammatory drugs can be used to help patients lower their body temperature. 3. Antiviral medication: Influenza A virus infection is commonly used oseltamivir for antiviral treatment, oseltamivir can inhibit the neuraminidase enzyme of influenza A virus, inhibit the release of the virus, and reduce the spread of the virus. Influenza A fever of 40 ℃ if the above measures are not effective, you should go to the hospital in a timely manner, under the guidance of the doctor to choose the appropriate drug treatment, to avoid the adverse effects of high fever.