ICU (Intensive Care Unit) critical care is specialized, 24/7 medical treatment for patients with life-threatening illnesses or injuries, using advanced equipment and highly trained staff to provide constant monitoring and life support for failing organs like lungs, heart, or kidneys. It's for severe conditions like major accidents, heart attacks, sepsis, or recovery from major surgery, aiming to stabilize patients and manage acute organ dysfunction with machines for breathing (ventilators), fluid/medication delivery (IVs), and vital sign tracking.