Her condition was critical, so the doctor recommended moving her to the ICU.

ICU 是 Intensive Care Unit 的首字母缩写，intensive 意思是"强化的、集中的"，care 指"医疗护理"，unit 指"医疗单位"。ICU 合起来指专门为危重病人提供24小时密切监护和强化治疗的"重症监护室"。