Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services now if PCP overdose is suspected.
Do not drive the affected person yourself if they are severely confused, violent, having a seizure, unconscious, or breathing abnormally.
Emergency signs include:
If they are not breathing normally, begin CPR if you know how and follow emergency-dispatch instructions.
New breathing difficulty, seizures, collapse, severe agitation, or rapidly worsening symptoms remain emergencies.
And for anyone, someone who:
For an exposure without severe symptoms, contact your local poison centre immediately for case-specific advice.
In the United States, Poison Help is available at 1-800-222-1222.
Do not wait for symptoms before calling.
After discharge, arrange routine follow-up for continuing confusion, sleep problems, low mood, hallucinations, muscle pain, dark urine, reduced urination, or concerns about drug use.
And for anyone, someone who:
The article also says
Move away from weapons, traffic, water, heights, and other hazards.
Keep the area as quiet as possible, and do not argue about hallucinations.
Do not try to physically overpower the person unless immediate safety requires it.
If the person is unconscious but breathing, place them on their side if this can be done safely.
Every sign above is quoted from the sofidex article on Phencyclidine overdose. If you are not sure, err upward — it is always reasonable to be checked.