Working in the dead of night: exploring the transition to after-hours duty.

First-year residents face multiple challenges during on-call, which may prevent optimal learning in this setting. These challenges are amplified by the large gap between the respective roles of medical students and residents. We identified promoters of and barriers to effective learning in this environment and, by using workplace learning theory, provide recommendations for how we might be able to enhance medical students' preparation for and first-year residents' learning during experiences of being on-call.