The warning signs are there for all to see. They include spontaneous outbreaks of silliness supported by episodes of reckless buffoonery. There is no doubt that discipline is teetering on the brink of total meltdown. Something has to be done before things get out of hand.
"It's not good enough," says our headteacher to her assembled audience. "Just because we're approaching the last day of term and you are about to enjoy six weeks away from the treadmill of factory-style learning, that doesn't mean normal standards of behaviour don't apply.
"I am going to say this once and once only: the giddiness, the puerile behaviour, the running along the corridors, the giggling, the screaming and the shouting stops right here, right now. Do I make myself clear?"
It's like someone has punctured the blow-up dolphin before it's even hit the hotel pool.
The sense of deflation is accompanied by nods of assent and a few grudging words of affirmation.
The headteacher takes a deep, calming breath, and says: "I mean, if my teachers can't show a degree of self-control, how can I expect the children to?"
Breaking up is hard to do
The title of Neil Sedaka's 1962 hit often applies to teachers at the end of a long school year. Against all the odds, they have retained their professional dignity. They have strived to maintain standards, fought to apply rules and wearily cajoled the last dregs of effort from those who would rather have given up at the first obstacle.
But it is a well documented fact that the most hazardous part of any journey is towards the end. That's when the brain relaxes, lowers its defences and disregards all warning signals.
This is why teachers on the last day of the year must guard against the urge to succumb to excessive jollity and wild frolics. They must resist the temptation to abandon the normal rules of restraint and run amok down the corridors of propriety. Instead, they must steel themselves for one last effort at professionalism. By following these six simple rules, teachers can avoid a last-day disaster.
Say a kind goodbye to the class of 2014-15
On the last day, we come to school with a song in our hearts. The past 11 months seem grim and grey compared to the lazy, hazy, crazy days of August that lie ahead. How tempting it is for a teacher - particularly one who has suffered the class from hell for three long terms - to celebrate the end of the academic year too early. How easy it is to appear overjoyed at never again having to do battle for the class of 2014-15's collective soul of learning.
Whatever we feel in our hearts, however, we must not allow our pupils to know the truth. The children should have no idea just how mightily relieved we are to be rid of them at last. Even the ones who caused our hearts to soar when they failed to arrive for morning registration - and grow heavy again when they loomed late in the doorway with a look of determination to make up for lost time - should leave feeling that they are part of a collective that was always valued.
The rule is not to let your class see you (metaphorically or literally) punching the air as you bid them farewell. Over the past year, you have seen some of these children more than their parents or carers have. You have been their guiding light, their fixed star and the rock upon which their nascent sense of self-worth has been tenuously founded. Think of the devastation you might cause if their attachment to you were to be shattered by the seismic revelation that you are overcome with delight at never having to teach them again.
By all means say your goodbyes with a song in your heart. But let it not be a wild and reckless rendition of Alice Cooper's School's Out. Now is not the time to risk undermining your professional credibility by appearing uncaring. Rather, it is a time for subtlety and cleverness. Figuratively speaking, let your final classroom performance be a heartfelt rendition of So Long, Farewell, as you watch them disappear one by one into someone else's future.
Say a charitable farewell to Nathan
There is always one student you will enjoy seeing the back of more than any other. He is the one who came to school every day, rain or shine, as though he were on a mission to make your life a misery. He is the one with a smile like a curved blade, who turned low-level disruption into an art form and made high-level confrontation an everyday occurrence.
And here he is on the last day of term, armed with that same smile and still acting like he owns your classroom. But today there is something different about him. For some reason, he wants to be your friend. He wants you to shake his hand and sign his leaver's T-shirt using the gold marker pen he denied having stolen from your drawer two days ago. Anyone would think he was never your torturer-in-chief - that he never called you vile names, wrecked your displays, shouted in your face or made lewd hand gestures at you through the window.
Well, now is the perfect opportunity to get your own back. Now is your chance to blank him completely and enjoy the sweet taste of revenge. But how would the other children interpret such an uncharitable act?
My advice is to rise above the tumult of petty emotions and act like a true professional. Make a point of seeking Nathan out. Put an arm around his shoulder. Tell him through gritted teeth just how much you will miss those "light-hearted" battles of will each day and the friendly banter that characterised his every refusal to work.
Then, with your own curved-blade smile, usher him gently out of the door and firmly into your past.
Bid an impartial adieu to Angelina
It isn't just the elation at seeing the back of a difficult class or a naughty student that can cause teachers to act unprofessionally on the last day of term. At a time of heightened emotions, unexpected feelings of sorrow and tearfulness may also serve to undermine your dignity. Are you really prepared for the moment when Angelina will hand you that gift-wrapped mug bearing the legend "best teacher ever" and sob with abandon in your arms?
It is as certain as changes to the national curriculum that every teacher has an Angelina in their class. She is the one child guaranteed to be polite, enthusiastic and well behaved. She is the ace up your sleeve during every lesson observation. Trying to hide the fact that she is the teacher's pet is a complete waste of time. Children are always more perceptive than we imagine.
In fact, they only tolerate your blatant favouritism because you sometimes play the game of impartiality with them. That's when you occasionally make a point of showing how fair you are by deliberately not rewarding Angelina the most, not praising her excessively and not choosing her to demonstrate good learning.
To be remembered for being even-handed, emotionally disciplined and not prone to blubbing, it is vital that you demonstrate a degree of restraint on the last day.
Remember to treat Angelina's weeping with the same condescending words and professional distance with which you treat all your other hysterical students, however painful it may be offer her no more solace than your best wishes, a brief hug and a box of tissues.
Be courteous to Ms Annoying
The thought of not seeing Ms Annoying for a while can bring about the same euphoria as the prospect of not seeing children for the next six weeks - and that can threaten a teacher's professional integrity at this time of year. After all, ours is a sector populated by people who not only think they know better than everyone else about what's best for everyone else, but also make a point of telling them.
It is a well-known fact that some teachers are unable to differentiate between their students and their colleagues; lecturing the latter as though they are the former can be a major source of irritation. The problem is worse where primary teachers like Ms Annoying are concerned. After all, her colleagues are not five-year-olds and don't appreciate having their faults explained to them in condescendingly short and clearly enunciated sentences.
But the rule today is to forgive and forget. Make a special effort to seek out Ms Annoying and thank her for all her help and advice over the year. And when you do this, resist the temptation to click your fingers for attention, to repeat things several times over and to speak irritatingly slowly.
Temper your joy with a little sadness
There will be moments during the last day, while your children are happily marauding around the classroom, when you will feel an urge to open your email account. Perhaps you need to reassure yourself that your online check-in has been completed. Or maybe you need to make one more virtual tour of your hotel complex.
I suggest that as you contemplate that EasyJet flight to Alicante, you temper your excitement by giving a thought to one or two of the children you will be leaving behind. I don't mean Nathan or Angelina. I mean the grey children: those pale ghosts who drift through lessons almost unnoticed, and who would drift through their entire childhood unrecorded if their names were not on the at-risk register. My advice is that you remind yourself, before you check the weather forecast for the Costa del Sol, that these children won't be jetting off to sunnier climes. The last day for them will not be a break from the endless grind but an increase in neglect and abuse.
It is a sobering thought that, for some children, school is as much a refuge as it is a place for learning. There is nothing like the reverse thrust of guilt to bring a teacher back down to the landing strip of life with a bump.
Stay sober until the `flat' lady sings
Even after the last bell has rung freedom and the children have melted away through the school gates like choc ices in the summer sun, it is important for teachers not to get too excited. When a premature glass of wine is mixed with over-celebration during the staff night out, words can slip out that later prove awkward and embarrassing.
Even at the end of a long and difficult year, the temptation to consume too much alcohol early in the evening must be resisted. It will almost inevitably lead to an airing of your more candid views on poor leadership, overbearing attitudes, intolerable opinions, inappropriate evening attire and the questionable morals of a certain Ms You-know-who.
To avoid a last-day meltdown - and an August filled with worry about facing your colleagues again at the start of the new term - my advice is to refrain from excessive alcohol consumption until after the "flat" lady sings. This usually happens at about 11pm when the headteacher gets on the karaoke and performs her disastrously out-of-tune rendition of Cliff Richard's Summer Holiday. Whatever you might do or say after that, it won't be the end of the world.
Then, and only then, as you wind your way home in a taxi, can you really embrace the holidays.
Go on, give a little yelp of joy. You know you deserve it.
Steve Eddison teaches at Arbourthorne Community Primary School in Sheffield