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 someone who has been drinking is difficult to wake, cannot stay conscious, has a seizure, or has slow, shallow, noisy, or irregular breathing.
Also call if their skin or lips look blue or unusually pale, they repeatedly vomit, or you suspect a head injury or mixed overdose.
Stay with the person and follow emergency instructions
If a child swallows alcohol or an alcohol-containing product, contact emergency services or a poison centre promptly, even if no symptoms are present.
And for anyone, someone who:
Seek same-day medical advice after persistent vomiting, worsening confusion, a possible injury, or symptoms that are not settling.
Routine follow-up is appropriate if poisoning, blackouts, or risky drinking have happened more than once.
The article also says
Do not assume the person can “sleep it off.” Their alcohol level may still rise, and an unconscious person can choke or stop breathing.
While waiting for help:
If unconscious but breathing, place them on their side
If they are not breathing normally, begin CPR if able
Keep them warm without using a hot bath or shower
Do not give coffee, food, more alcohol, or a cold shower
Do not make them walk or try to make them vomit
Tell responders what was consumed, when, and how much
Every sign above is quoted from the sofidex article on Ethanol poisoning. If you are not sure, err upward — it is always reasonable to be checked.