I was a special constable with Thames Valley Police for a number of years in the early part of my teaching life. I would often work the 6pm to 2am shift on a Friday or Saturday night after a week’s teachering, and I can confidently say that I became much better at dealing with behaviour back in school as a result.

One of the most memorable parts of the selection process involved being asked to stand in front of the other candidates and choose a number between one and 50. I was first up, and said confidently “One”.

“Right,” the inspector said, “you have two minutes to talk about potatoes”.

So, there I was in front of a group of a dozen or so people, winging it. I remember talking about Henry VIII, the Irish potato famine, Sir Francis Drake and the Golden Hind. I made almost all of it up, but that wasn’t the point. It was designed to put me in a situation of pressure with absolutely no preparation or knowledge of what was to come and yet maintain an outward aura of calm authority and control.

It is something police officers face all the time and, as teachers, we occasionally find ourselves in similar situations. Perhaps a fight breaks out when you’re on duty at lunchtime, or maybe it’s your lesson that one of the children in the fight storms into afterwards, slamming the door, exclaiming that “Sean’s a dead man after school and so is anyone else who tries to stop me!”

It is at times like these when everyone else looks to you to save the day, despite the fact that you may not have the first clue what to do.

A big part of dealing with such situations effectively is how you convey to everyone that you’re going to sort this: clear, concise instructions, even if, deep down, you have no idea what’s going to happen next; a firm, authoritative voice without shouting, which can suggest a loss of control; positive body language, which means not cornering people or towering over them; and, most importantly, internalising your own stress. It’s not easy, but it is vital, as your demeanour can reassure everyone around you or unnecessarily escalate a situation, which is the last thing you want.

There is also nothing wrong in seeking support. “Daniel, please pop next door and tell Mrs Barker that Mr O’Brien needs her now. Thank you,” is a smart move. Then, when help does arrive, you can tackle the situation between the two of you.

Whatever you do, don’t do what one of my fellow trainee special constables did when we were learning how to stop and search people. The instructor, a former French Foreign Legionnaire, started by shouting in French. The candidate let out a tiny scream, turned around and ran away.

Jarlath O’Brien is director for schools at The Eden Academy. His latest book, Better Behaviour: A Guide for Teachers, will be published by SAGE in 2018