In critically ill Yellow Fever patients, the ICU focuses on aggressive supportive care because there is no specific antiviral treatment: patients may need mechanical ventilation for breathing failure, dialysis (renal replacement therapy) if the kidneys stop working, IV fluids and vasopressors to maintain blood pressure, blood and platelet transfusions to control bleeding, continuous monitoring of liver function and clotting, careful fever and glucose control, and strict infection prevention, with round-the-clock critical care support aimed at stabilizing organs while the body recovers.