Teams have become the norm for operating in dangerous and complex situations. To investigate how physical threat affects team performance, 27 three-person teams engaged in a complex planning and problem-solving task, either under physical threat or under normal conditions. Threat consisted of the possibility that during task performance the oxygen level would be reduced (which, in reality, did not occur). Team processes were measured by automated behavior recordings and questionnaires. Results confirmed that physical threat caused restrictions in information processing, more controlling leadership, less group discussions, and a reduction in coordinating and supporting behavior. These results support the propositions of the threat-rigidity thesis and extend previous research by establishing these results for physical threat and demonstrating effects on coordinating and supporting behavior as well.