Critical-care settings have an opportunity to create healing environments (HEs). For the last decade, achieving this goal has been the task of the American Association of Critical Care Nurses. Today, several models used in these settings embrace synergistic care, healing therapies for patients, and the development of organizational models to improve the HEs for nurses themselves. Creating the HE is not impossible; however, researching the patient's experience within it is complex. This complexity requires researchers to consider biological, behavioral, and social variables on the unit. This article will describe biological and behavioral measures that may be used to examine the critically ill patient's response to an HE. Limitations of these measures are considerable. Future researchers will need to consider a multiplistic approach to the study of this construct.