We are investigating the potential of 3D telepresence, or televideo, technology to support collaboration among geographically separated medical personnel in trauma emergency care situations. 3D telepresence technology has the potential to provide richer visual information than current 2D videoconferencing techniques. This may be of benefit in diagnosing and treating patients in emergency situations where specialized medical expertise is not locally available. The 3D telepresence technology does not yet exist, and there is a need to understand its potential before resources are spent on its development and deployment. This poses a complex challenge. How can we evaluate the potential impact of a technology within complex, dynamic work contexts when the technology does not yet exist? To address this challenge, we conducted an experiment with a posttest, between-subjects design that takes the medical situation and context into account. In the experiment, we simulated an emergency medical situation involving practicing paramedics and physicians, collaborating remotely via two conditions: with today's 2D videoconferencing and a 3D telepresence proxy. In this article, we examine information sharing between the attending paramedic and collaborating physician. Postquestionnaire data illustrate that the information provided by the physician was perceived to be more useful by the paramedic in the 3D proxy condition than in the 2D condition; however, data pertaining to the quality of interaction and trust between the collaborating physician and paramedic show mixed results. Postinterview data help explain these results.