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 immediately for:
Trouble breathing or noisy breathing
Severe or rapidly increasing throat or tongue swelling
Blue, grey, or unusually pale lips or skin
Collapse, severe drowsiness, or unresponsiveness
Choking or inability to swallow saliva
Keep them away from further plant contact and follow emergency instructions while help is on the way.
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
Seek prompt medical care if:
Mouth or tongue swelling is increasing
Pain prevents normal drinking
Vomiting continues
Drooling or difficulty swallowing does not improve
Eye pain, redness, blurred vision, or light sensitivity continues after rinsing
Skin symptoms are severe, widespread, blistering, or persistent
The article also says
Call a poison centre after a suspected bite or ingestion, particularly when a child is involved, the plant is uncertain, or symptoms have started.
Poison specialists can help decide whether home observation or an in-person assessment is appropriate.
Do not drive someone who is having breathing difficulty.
Every sign above is quoted from the sofidex article on Philodendron poisoning. If you are not sure, err upward — it is always reasonable to be checked.