Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call your local emergency number or go to an emergency department if there is immediate danger, a suicide plan or attempt, serious threats, extreme agitation, or severe unresponsiveness.
This needs emergency medical assessment.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Arrange a routine or prompt mental health review if:
Hallucinations, suspiciousness, or unusual beliefs are returning
Sleep, self-care, concentration, or daily functioning is getting worse
Medicine side effects are troubling or affecting treatment
Doses have been missed or treatment has been stopped
Depression, anxiety, alcohol use, or drug use is increasing
Seek urgent help if someone is becoming severely confused, cannot care for basic needs, has gone without food or fluids, or is responding to voices that tell them to do dangerous things.
The article also says
Fever, marked muscle stiffness, confusion, and heavy sweating while taking an antipsychotic can signal a rare but serious reaction.
If you are helping someone in crisis, stay calm, reduce noise and confrontation, and focus on immediate safety.
Do not argue aggressively about whether a belief or voice is real.
Every sign above is quoted from the sofidex article on Schizophrenia. If you are not sure, err upward — it is always reasonable to be checked.