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 emergency services now if there is:
Severe trouble breathing, blue or grey lips, or intense chest pain
Collapse, a seizure, severe confusion, or difficulty waking
Repeated or bloody vomiting
Severe abdominal pain
Very little or no urine after a suspected exposure
Get urgent poison-control or emergency medical advice after any suspected swallowing of mercuric oxide, meaningful inhalation of its dust, or exposure to fumes from heated material.
Do this even if symptoms have not started.
Elsewhere, contact your local poison information service or emergency number.
And for anyone, someone who:
you believe has taken an overdose or swallowed something poisonous
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
2
Is any of this happening?
Be seen today
Eye exposure, a large skin contamination, or an exposure involving a child also needs prompt advice.
In the United States, Poison Control is available at 1-800-222-1222.
3
Does any of this apply?
Book an appointment
Routine follow-up is important after confirmed poisoning.
Arrange review if tremor, memory problems, mouth soreness, swelling, reduced urination, or breathing symptoms continue or return.
Attend planned blood and urine testing even when you feel well.
Every sign above is quoted from the sofidex article on Mercuric oxide poisoning. If you are not sure, err upward — it is always reasonable to be checked.