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 the exposed person:
Has trouble breathing, severe wheezing, or noisy breathing
Collapses, has a seizure, or cannot be awakened
Has rapidly increasing swelling of the mouth, tongue, or throat
Vomits blood or has severe chest or abdominal pain
Has signs of a serious eye injury or sudden loss of vision
Swallowing a hair straightener or relaxer needs immediate advice from a poison centre or emergency service, even if symptoms are mild.
Arrange routine follow-up after emergency care if swallowing remains painful, food begins sticking, a burn is not healing, or cough and wheezing keep returning.
These symptoms can reflect a complication that needs assessment but are not always an emergency.
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
Do not wait for pain or vomiting to develop.
For an eye or skin exposure, begin rinsing immediately and contact a poison centre for instructions specific to the product.
Urgent assessment is needed if pain, redness, blistering, blurred vision, coughing, or breathing symptoms continue after rinsing or fresh air.
Every sign above is quoted from the sofidex article on Hair straightener poisoning. If you are not sure, err upward — it is always reasonable to be checked.