Your goal: call for help, provide your location, and explain what has happened. Calm, direct communication to ensure safety.
Dispatcher: Emergency service. Which service do you require?
Caller: Ambulance, please! My friend collapsed.
Dispatcher: What is your exact address?
Caller: 12 Green Street, Apartment 3.
Dispatcher: Is he breathing?
Caller: Yes, but he is unconscious.
Dispatcher: Stay on the line. The ambulance is on the way.
Numbers vary by country, but these are common: