Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services now if the person:
If they are not breathing normally, begin emergency first aid if you know how and follow the emergency operator's instructions.
And for anyone, someone who:
Call a poison control service promptly if someone has swallowed concentrated peppermint oil or taken more peppermint oil medicine than the label directs.
Do not wait for symptoms, especially when a child is involved or the amount is uncertain.
Seek urgent medical advice for ongoing vomiting, marked dizziness, unusual sleepiness, poor coordination, reduced urine, blood in the urine, or persistent abdominal pain.
New breathing problems, reduced alertness, or seizures are not routine follow-up concerns and need urgent care.
Routine follow-up is suitable after the immediate risk has passed if mild symptoms continue, test results need rechecking, or the treating team requested another review.
And for anyone, someone who:
The article also says
If the person is unconscious but breathing, place them on their side if it is safe to do so.
Do not put anything in their mouth.
Every sign above is quoted from the sofidex article on Peppermint oil overdose. If you are not sure, err upward — it is always reasonable to be checked.