`You have to be sure to wear a warm coat," says Mary Murray, a teacher at Ratoath National School in Co Meath. She teaches a class of junior infants. When her day for yard duty comes around once a week, she prepares for a stressful, intensive day without a break. "You have to ask someone to mind your class when you go to the toilet," she says.

"During the day you don't get a chance to talk to another adult. You don't get time to think. You depend on the rest of the staff to accommodate you. I have to eat my lunch with the children."

During a 10-minute lunch-time in class, while she eats her sandwiches, she has to help the class of four- and five-year-olds to open their little milk cartons, peel their oranges and see that they have spoons for the yoghurt.

"You might get to finish your sandwich outside as you go up and down the yard. If you have to tie their laces, you have to hold your sandwich in your mouth.

"You don't have a minute for the whole day. If you'd had a stressful time the night before, if your own baby hadn't slept or you have a cold, you're exhausted. You can't have a cup of tea, there's no option unless you bring in a flask."

With 460 pupils and three yards to supervise, the Ratoath rota comes around once a week for each of the 16 teachers.

"Every day you wake up and you realise you're on yard duty, it changes your whole plan for the day," says Murray. "You change what you wear. You make sure you wear warm clothes. You have to plan for yard duty as well as your actual teaching day.

"Junior infants are very intensive. You can't give yourself a two-minute break. You have to give them total attention. You're their surrogate mother. In the yard you have to tie their laces, give them a hug, wipe their wounds. You can't take your eyes off them. You have to watch that they don't fall, that they're not fighting, that they're not crying."