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 severe breathing difficulty, collapse, seizure, confusion, blue or gray lips, or inability to wake the person.
And for anyone, someone who:
Seek urgent medical care for worsening pain, spreading redness, fever, reduced urination, increasing weakness, or new breathing problems.
Follow-up is based on the type and severity of exposure.
A small exposure that remains symptom-free may only require poison-center guidance, while a burn, eye exposure, ingestion, or systemic illness usually needs medical follow-up.
Burn follow-up can assess healing, infection, scarring, sensation, and movement around joints.
An eye specialist may monitor vision and healing after eye contact.
The article also says
Clinicians may repeat kidney, liver, blood, or urine tests after a significant exposure.
After swallowing phenol, report new or worsening trouble swallowing, repeated vomiting, chest pain, abdominal pain, or unintended weight loss.
These may require evaluation for delayed injury or narrowing of the esophagus.
Before returning to a workplace where phenol is used, review the incident with occupational health or workplace safety staff.
The review may identify a need for better ventilation, protective equipment, storage practices, spill procedures, or training.
Every sign above is quoted from the sofidex article on Carbolic acid poisoning. If you are not sure, err upward — it is always reasonable to be checked.