Fever is clinically known as fever, fever of 40 ℃ belongs to high fever, there is no absolute sense of the best treatment for high fever, according to the cause of the disease can be given relative treatment. 1. Infectious factors: may be subject to bacteria, viruses and other pathogenic microorganisms invade the body, there may be fever to 40 ℃. You can take acetaminophen tablets and other drugs to reduce fever; if it is a bacterial infection, then intravenous ceftriaxone sodium and other antibiotics to reduce inflammation; if it is a viral infection, then intravenous ribavirin and other drugs to fight the virus. 2. Connective tissue diseases: due to the patient’s immune function disorders, antigen and antibody immune complexes generate too much, leading to inflammatory lesions and immune response within the body, resulting in a high fever of 40 ℃ recurrent episodes of the performance of the common rheumatoid arthritis. Can be prescribed oral leflunomide tablets and other drugs to regulate the immune function; oral diclofenac sodium capsules and other drugs analgesic anti-inflammatory; oral ibuprofen capsules and other drugs to reduce fever. It is recommended that patients with fever be treated promptly at the beginning of the rise in temperature, and not wait until the development of hyperthermia to begin to pay attention to it, so as not to damage the brain and cause complications. Drugs should be used in accordance with medical advice.