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 for new breathing difficulty, a seizure, collapse, inability to wake the person, or rapidly worsening symptoms.
And for anyone, someone who:
Seek prompt reassessment if vomiting continues, coughing or fever develops after vomiting, eye symptoms persist, or the person remains unusually tired, unsteady, or confused.
After medical treatment, routine follow-up may be recommended if there was aspiration, an abnormal blood test, ongoing stomach symptoms, an eye injury, or a significant underlying health condition.
Children should return to their usual alertness, eating, drinking, and activity level.
If intentional ingestion occurred, follow-up should address emotional safety, access to harmful substances, and ongoing mental health support.
The article also says
Follow the observation instructions given by Poison Control or the treating clinician.
A person who remains completely well after a minor exposure may need only home monitoring, but this decision should be based on the product and circumstances.
Store cologne in its original labeled container, tightly closed and out of children’s sight and reach.
Do not transfer it into a cup, water bottle, or food container.
Every sign above is quoted from the sofidex article on Cologne poisoning. If you are not sure, err upward — it is always reasonable to be checked.