self collected

/ˌsɛlf kəˈlɛktɪd/
adjective
  1. Calm and in control of one's emotions, especially in a difficult situation.
    • He was surprisingly self-collected during the job interview, answering every question with poise.
    • Even during the emergency, she remained self-collected and gave clear instructions.
    • The teacher stayed self-collected when the fire alarm went off, guiding students calmly to the exit.