We could always tell, about two minutes beforehand, whenever our old maths teacher was going to self-combust again. 

First the neck would redden. Then his towering body would start swaying forwards and back in that buttoned-up suit, rocking on the heels so much that some of the young comedians in the front row would start taking refuge beneath their desks. 

Finally, he would let out a thunderous “Enough!” Sadly, it rarely was. 

I envy colleagues who - unlike my old maths teacher and now me - spend their entire careers remaining utterly calm and cool in every lesson. Absolutely anything might happen and they would just take it in their stride. 

By contrast, some of us regularly feel something smouldering within us. We can usually quell that fire, but there are still particular points in the school year when all the tiredness and end-of-year demands and deadlines can cause our fuses to shorten by the day. Like now, for instance. And never more so than towards the end of this particular year. 

Classroom management: The all-revealing tell

The interesting (and potentially helpful) feature is that those of us prone to losing it do have a “tell” at such times - some small but noticeable sign beforehand that indicates that we are shortly going to go off on one, as with my old maths teacher. 

The tell might indeed be a neck going red, or a rapid blinking of the eyes, a standing on one leg, a scratching of the head, or a playing with our hair, or the back of the hand involuntarily moving over the mouth. The class always get to know those early-warning signals. “Here he goes,” we can almost hear some of them mutter to each other.  

My own tell - so I have been assured by several students - is that I start opening more windows. The room, of course, isn’t getting any hotter. Just me. 

What makes things worse for me is that I am also utterly useless when doing rage. I’m so cross that the words of admonishment coming out from my mouth are always slightly different from the ones I wanted to say - or indeed, that anyone would want to say.  

Alternatively, I do use all the words I intended, but in a slightly random order. Either way, my subsequent pause for class reflection after delivering my speech merely gives everyone more time to reflect on the nonsense I have just delivered. It’s then just a question of us all trying to keep a straight face. 

Disclosing our early-warning signs

Other people’s pre-eruption tells might be more verbal. One former colleague used to go “Er!” repeatedly whenever she was about to explode. She hated herself for it - it made her sound “so old-school”, she complained. 

One teacher, briefly over from Australia, could frequently be heard to say “Wading” (ie, “waiting”) whenever his class was getting out of hand. This made no real difference - he “waded” a long time. Eventually he would wade no longer and delivered his antipodean verbal onslaught.

Such displays of genuine loss of temper might bring some brief corrective behaviour, but they rarely help in the long run. We know we have basically lost, whenever it happens. 

So maybe it’s time we emotionals make more positive use out of those tells, those early-warning signs? 

Why don’t we be proactive and disclose our tell to one of the more sensible and discreet children at the front of the room? Then they can quietly alert us whenever we start to show the familiar signs. “Sir, you’re doing the windows thing. Maybe take a time-out for five minutes?”

Maybe this version of pupil voice could help avoid more storms and help us all sail more calmly into the harbour at the end of term. 

Stephen Petty is head of humanities at Lord Williams’s School in Thame, Oxfordshire