Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency help if the person:
Call local emergency services or go to an emergency department.
If it is safe, stay with the person, reduce noise and stimulation, and speak in short, calm sentences.
Do not argue about whether a hallucination or delusion is real.
Avoid physical restraint unless trained emergency professionals determine it is necessary.
Contact the treating clinician urgently if psychotic symptoms return, sleep falls sharply for several nights, behavior becomes increasingly confused, medicine side effects are significant, or the person is struggling to eat, drink, or care for themselves.
Early follow-up is usually closer and more frequent than long-term care.
Appointments allow the clinician to confirm that symptoms are resolving, review sleep and daily functioning, check medicine effects, and update the diagnosis if needed.
Routine follow-up should also address the emotional effect of the episode.
People may feel embarrassed, frightened, depressed, or uncertain about returning to work and relationships.
These reactions deserve attention and support.
The article also says
After recovery, the person and care team can make a written plan describing early warning signs and who to contact.
Warning signs may include reduced sleep, growing suspiciousness, social withdrawal, unusual beliefs, hearing voices, confused speech, or difficulty managing basic tasks.
Every sign above is quoted from the sofidex article on Brief psychotic disorder. If you are not sure, err upward — it is always reasonable to be checked.