When the disease made by the virus becomes a threat to life or organs blood circulation decreases, and the Temperature of the fever will emerge to increase the prevailing blood circulation. And it acts as a protective covering of the body to sustain life. When blood flow decreases to the brain, the patient becomes fainted-delirious. If we try to decrease the temperature of the fever, the blood circulation will further be reduced. Blood circulation never increases without a temperature increase. Delirious can never be cured without an increase in blood circulation. The temperature of fever is not a surplus temperature or it is not to be eliminated from the body. During fever, our body temperature increases like a brooding hen`s increased body temperature. The actual treatment for fever is to increase blood circulation. Two ways to increase blood circulation. 1. Never allow body temperature to lose 2. Apply heat from outside to the body. When the temperature produced by the body due to fever and heat which we applied to the body combined together, the blood circulation increases. Then the body will stop producing heat to increase blood circulation. And the body will get extra heat from outside without any usage of energy. How can we prove that the temperature of fever in Covid -19 is to increase blood circulation? If we ask any type of question related to fever by assuming that the temperature of fever is to increase blood circulation we will get a clear answer. I avoid or evade this definition we will never get a proper answer to even a single question If we do any type of treatment by assuming that the temperature of fever is to increase blood circulation, the body will accept, at the same time body will resist whatever treatment to decrease blood circulation.If we measure the heat energy used for which activities in fever, we will know the purpose of the temperature of fever. No further evidence is required to prove the temperature of fever in Covid -19 is to increase blood circulation.