Transitions between shifts in the intensive care unit (ICU) create potential gaps in the continuity of care, and practitioners necessarily rely on distributed cognition to prevent the formation of gaps during work-cycle shift changes. The complexity and uncertainty of each ICU patient's condition require efficient communication between practitioners during transfers between departments or when cycling work through shifts. This study observed twelve unit-level exchanges among six clinicians handing off a 33-bed PICU and step-down unit, then examined them using conversation analysis. Our research shows that pediatric ICU fellow sign-outs demonstrate high context sensitivity, compact reference, gestures, and stylized expressions. We find that sign outs account for both what is known and what is not known about a patient's condition, and to assess expectations for the oncoming shift. Uncertainty about patient condition influences handoff content and form. Clinicians change the amount time that they allocate to handoffs based on other aspects of work load, such as rounds or procedures. Clinicians apportion time to discuss individual patients according to the perceived severity and stability of each patient's condition. Expertise in hand-off communications depends on the ability to prioritize relevant information and to transfer insights effectively. Relevant, efficient hand-offs significantly affect the ability of clinicians to provide care at the unit level, within and between departments, and across specialties such as intensivists, nurse anesthetists, and anesthesia technicians. Even though they affect patient care quality and continuity, sign outs are not taught but are instead learned on the job. Formal study of, and training in, the conduct of sign outs may benefit both care providers and patients alike.