When I arrived with a big group of students at the NEC, more or less on time, to attend the Big Bang Fair, I couldn’t help patting myself on the back. This was a teaching milestone: here I was, leading my very first school trip.

This was my trainee year (back when school trips were actually allowed) and leading a trip seemed like the perfect challenge for me. I’m an extremely organised individual, so the numerous risk assessments, bus enquiries and consent forms that come with trips are just my cup of tea.

Everything that I needed was sorted in good time. I had a full set of documents ready to go, with copies made. What could go wrong?

When the day came, we got off to a good start. The journey went smoothly. Once we arrived at the fair, students went off in small groups to experience everything that was on offer. The groups always came back to the meeting spots on time, everyone had remembered their lunches and a good time was had by all.

I was buoyed by the experience, and already congratulating myself on a job well done. Perhaps this misplaced confidence was what prompted me to agree when my students asked if they could buy iced-tea coolers from a coffee shop as we were waiting for the bus.

I didn’t see the harm. We’d done our toilet visit and still had a good 25 minutes before we were due to leave. Besides, the students had been fantastic all day and deserved the reward. How could I say no?

“Sure, go ahead,” I said. The queue seemed a little long but not too bad. We had plenty of time, after all.

But as the minutes ticked by, I realised that I had made a mistake.

With 10 minutes to go, the students had only just ordered and paid. And when the time came for us to be back on the bus, there was still no sign of their drinks. I was starting to panic. Should I make us leave, forcing my students to lose their money? Or should I keep everyone else waiting?

Around 15 missed calls later, my group and I were sprinting back to the bus, where we found a furious driver and the other students, who quickly became annoyed that they hadn’t also been allowed to buy coolers.

My seemingly innocent reward had opened an enormous can of worms. Now the bus driver would be late to his next job and I had to spend the ride home phoning parents to tell them why their children wouldn’t be ready to be collected at the agreed time.

There is an important lesson to take from this: we must always consider the wider consequences of the rewards we hand out. What can seem like a nice way to acknowledge good behaviour can actually create headaches for colleagues and make other students feel left out.

Of course students deserve recognition for getting it right but that shouldn’t come at the expense of others. It may not be much fun to sit on a stationary bus for 25 minutes but, if the alternative is inconveniencing colleagues and alienating half a class, then sitting on a bus is fine by me.

Nathan Burns is a maths teacher, and an assistant progress and achievement leader for key stage 3

This article originally appeared in the 2 April 2021 issue under the headline “The iced tea cometh a bit late”