The instruction stay calm can become another demand placed on the person already overwhelmed.

Telling someone to stay calm hands them one more thing to fail at. They are already managing the situation and their own reaction, and now composure has become an additional requirement, judged by whoever is watching. The instruction usually serves the speaker’s discomfort more than the person receiving it.

What helps instead is something specific and doable: hold this, sit here, tell me the last thing that happened. Concrete tasks steady people in a way that instructions about their emotional state cannot. And when you are the one being told to calm down, the frustration you feel about it is reasonable, and is not evidence that you are handling anything badly.