It’s often said that this half-term is the worst for staff absence. Schools find their cover supervisor availability is stretched and their supply agency costs high. But middle managers are the ones who tend to bear the brunt of all this teacher illness.

I did that typical teacher thing during the half-term break: struggled through to the last Friday, spent the weekend sleeping, dragged myself to the chemist’s on Monday for Lemsip, and spent much of the week sniffing and feeling sorry for myself. No matter, though. Being ill in the holidays is not so bad. Compared with being ill in term time, it’s a breeze.

Like any teacher, as a head of department you have to set lessons for your classes if you are ill. No matter whether you can barely hold the phone receiver to call in to school, Year 11 will be sitting in their usual seats waiting for your planned lesson to start. The work doesn’t stop and wait for you to get better.

When you are back, you will have students’ half-done work to mark, schemes of work to catch up on, a messy desk to clear and a staffroom pigeon-hole to sift through. Observations you missed will need to be rescheduled, minutes from middle leaders’ meetings will have to be read and acted on, not to mention the raft of questions facing you from other members of your department.

Then there’s the illness of members of your team. While you email in lessons from your sickbed, your colleagues might not be quite so generous of spirit, leaving you to set up six lessons, photocopy the resources, check that Year 10 haven’t driven the cover teacher to tears, and anticipate the same the following day.

The moral? In anticipation of the Christmas holidays, take echinacea and have a stock of one-off cover lessons ready to go. On quiet days, when nobody seems to need you and your team is functioning on full power, be sure to look after yourself. No one is indispensable, but middle leaders are more indispensable than most.

Josephine Smith, Deputy headteacher of Long Field High in Leicestershire.