People often say, "A small move may affect the bigger picture." A small cold can be life-threatening, highlighting how fragile the human body is. Each organ is interconnected — like dominos, if one piece falls, the rest will eventually fall as well under mounting pressure. Therefore, no pathogenic factor should be underestimated; even a tiny trigger can lead to a life-threatening crisis. In the ICU, patients' conditions are more urgent, severe, and complex, requiring doctors to carefully consider each step of treatment, weighing the pros and cons to choose the most beneficial plan. The book narrates 48 compelling ICU cases, hoping to leave a lasting impression on readers and provide useful assistance in critical moments.