That's Cytokines Storm Syndrome, acute systemic inflammatory syndrome characterized by fever and multiple organ dysfunction.
The central character of this storm is interleukin 6 receptor (IL-6). IL-6 is produced mostly by activated leukocytes and acts on a large number of cells and tissues. It promotes the growth of some categories of cells and inhibits the growth of some other. It also stimulates the production of acute-phase proteins and plays an important role in thermoregulation, in bone maintenance and in the functionality of the central nervous system.
Although the main role played by IL-6 is pro-inflammatory, it can also have anti-inflammatory effects. In turn, IL-6 increases during infections, inflammatory diseases, autoimmune disorders, cardiovascular diseases and some types of cancer.
Actemera (Tocilizumab) is a popular treatment for Cytokines Storm Syndrome. Its an immunosuppressant drug.