Our overall view is that many, if not most patients meet the challenge of acute, severe illness or injury with admirable equanimity and fortitude. The physical setting itself of the critical care unit, forbidding as it appears to the uninitiated and to even some medical and nursing staff elsewhere in the hospital, need not be unduly stressful to the patient if he senses the human concern, interest, and caring attitude of the medical and nursing staff in whose hands his life and welfare has been placed. The humanizing element of person-to-person contact is capable of rapidly desensitizing the patient to any alarm, fear, or bewilderment. An understanding of basic neurobiological and psychological principles in constructing a medical and nursing care program for the critically ill is fundamental to improving the quality of the experience for the patient, and may well contribute significantly to a lowered mortality risk for certain instances of illness or injury.