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
Treat any known or suspected hydrofluoric acid exposure as an emergency.
Begin rinsing immediately and call emergency services or your regional poison center.
Pain does not need to be present before you seek help.
Emergency help is especially important after:
Any eye exposure or swallowing
Breathing fumes, mist, or gas
Exposure to a concentrated or unknown-strength product
Contact over a large area or beneath a nail
Chest pain, breathing difficulty, weakness, confusion, or muscle cramps
Fainting, seizures, or a fast or irregular heartbeat
After emergency treatment, attend planned wound, eye, lung, or burn follow-up.
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
Contact the treating service sooner if pain returns, the wound deepens, movement decreases, or symptoms begin to worsen.
The article also says
Do not drive yourself if you feel unwell or if systemic poisoning is possible.
Bring the product label or safety data sheet if this can be done without delaying care or causing further exposure.
Every sign above is quoted from the sofidex article on Hydrofluoric acid poisoning. If you are not sure, err upward — it is always reasonable to be checked.