During a natural disaster such as hurricane, earthquake, or fre, robots have the potential to explore vast areas and provide valuable aid in search & rescue efforts. These scenarios are often high-pressure and time-critical with dynamicallychanging task goals. One limitation to these large scale deployments is effective human-robot interaction. Prior work shows that collaboration between one human and one robot benefits from shared control. Here we evaluate the effcacy of shared control for human-swarm teaming in an immersive virtual reality environment. Although there are many human-swarminteraction paradigms, few are evaluated in high-pressure settings representative of their intended end use. We have developed an open-source virtual reality testbed for realistic evaluation of human-swarm teaming performance under pressure. We conduct a user study (n=16) comparing four human-swarm paradigms to a baseline condition with no robotic assistance. Shared control signifcantly reduces the number of instructions needed to operate the robots. While shared control leads to marginally improved team performance in experienced participants, novices perform best when the robots are fully autonomous. Our experimental results suggest that in immersive, high-pressure settings, the benefts of robotic assistance may depend on how the human and robots interact and the human operator’s expertise.