In the US, when people call 911 it's normal for them to begin with, "Hello? 911? Yes, [insert emergency explanation here.]"
I know the number's 999 in the UK, but do people normally begin the conversation with the number like they do in the US or do they use the term "emergency services" or something similar?
EDIT: Just to clear things up a bit. I'm referring to what the caller calls it rather than the operator him/herself. It's for a monologue phone call, so the reader never gets to hear the operator's side of it anyway.
EDIT 2: Thank you to everyone who replied. I think I've got it. To those who were saying "Hello? 911?" is unrealistic. Well, yes it is. I've called 911 myself, so I know how they answer their calls. But the story in question is a short story about a man and his wife that almost get strangled by their vacuum cleaner when it mysteriously comes to life. It begins with his one-sided call to the emergency services. So... yeah. Sorry about the confusion.