39 ℃ more than three days of fever is something, a long time repeated high fever is easy to cause depression, dizziness, headache and other symptoms; repeated high fever is easy to cause convulsions and even convulsions, can induce epilepsy; can cause respiratory failure and heart failure and other serious complications. 1. cause mental depression, dizziness, headache and other symptoms: fever is the body’s immune response, if the body temperature is not high and does not last long, it is generally not harmful to the human body, but if the fever is repeated for three days, it can make the human body depressed, dizziness, headache and other symptoms. 2. cause convulsions or even convulsions can induce epilepsy: repeated high fever for three days may produce some irreversible damage to brain cells or brain function. Repeated high fever can easily cause febrile convulsions (convulsions due to high fever) and can even induce epilepsy. 3. If the fever is caused by inflammation of the lungs, prolonged high fever can lead to serious complications such as respiratory failure and heart failure. Persistent fever more than 38.5 ℃ need to go to the hospital, under the guidance of the doctor to correctly carry out the treatment, you can not just randomly use drugs.