Adult fever to 39 ℃ belongs to high fever, this situation how to reduce fever the fastest, there are roughly the following aspects: First, should be applied to the injection or intravenous drip to reduce fever, you can choose to use analgin intramuscular injection or choose lysergic acid intravenous drip to reduce fever, so the effect is better. Second, you can also temporarily take oral antipyretic drugs, such as the commonly used clinical ibuprofen granules or ibuprofen suspension, you can also take acetaminophen or Tylenol and other antipyretic drugs for treatment. Third, some physical therapy methods of Chinese medicine can also play a role in reducing fever, such as scraping therapy, bloodletting therapy, acupuncture therapy and tui na therapy, all of which have good effects. Through the above analysis, adults with fever up to 39℃ should apply the above methods and do relevant tests, including routine blood tests, C-reactive protein and other relevant tests to determine whether the fever is caused by inflammatory infection or viral infection.