Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Treat suspected paraquat swallowing as an emergency.
Call your local emergency number and poison centre immediately.
Emergency assessment is also needed after a significant eye splash, soaked clothing, contact with broken skin, or inhalation of concentrated spray.
Move away from the source without exposing other people.
If it is safe, remove contaminated clothing and begin rinsing exposed skin or eyes while help is arranged.
Blue or grey lips, severe breathing difficulty, collapse, or reduced responsiveness require emergency services.
And for anyone, someone who:
Do not wait for symptoms.
After hospital discharge, seek urgent medical care for:
Routine follow-up is appropriate for planned blood tests, breathing checks, wound review, and rehabilitation when no new warning symptoms are present.
The article also says
Do not drive yourself if you are unwell.
Do not handle a leaking container to bring it with you.
Give responders the product name or a photograph of the label if this can be done safely.
Every sign above is quoted from the sofidex article on Paraquat poisoning. If you are not sure, err upward — it is always reasonable to be checked.