Since 2001 we have been involved with Ceredigion’s healthy schools network, which encourages schools to look at all issues that affect pupils’ health, including emotional wellbeing, drugs and alcohol awareness, environmental concerns and healthy workplace issues. We addressed nutrition as part of our accreditation as a healthy school. Strategies include making an attractive menu board, designing and making healthy lunches, making children aware of the benefits of each food type on their plate every lunch time, celebrating organic food week, celebrating vegetarian food week, having access to raisins during lessons to graze, and creating a school fruit shop.

Hydration is an important part of this. Each child has a water bottle with his or her name on it. They are colourful and have important facts about water written on their sides, which reinforce the importance and benefits of hydration. The children fill their bottles, which cost pound;1 each, before the start of the school day, keeping them on their desks - we encourage children to drink water in the classroom - and refilling them during break times. This means minimal disruption to teaching time.

Children learn best when they are in an appropriate physical and emotional state. The brain needs water to function efficiently; water conducts tiny electrical currents that drive it, removes waste and toxins from the body and allows significantly more oxygen to bind to red blood cells. We need about 1.5 litres each day and up to three times as much when we are under stress. When people are dehydrated, learning is impaired as mood and concentration deteriorate.

Since we introduced water bottles into the classroom, the children’s concentration is better (especially the 20 minutes before lunch and at the end of the day), they are more alert and their memory has improved. There have been no negative effects - not even the expected mass exodus to the toilets during lessons. I have also started to drink more water, and feel the same benefits.

The bottles are popular and the children are now fully aware of the benefits of drinking water. Typical comments include: “Water keeps me awake all day”, “I don’t feel as tired in the mornings”, “I feel fresher for longer”, “It helps me concentrate and I work harder”, “It helps me concentrate more and gives me more energy”, “Water helps me think” and “When I’m tired it wakes me up”.

Parents have welcomed the scheme and are supportive. Visitors are intrigued, and always ask about the bottles.

There are some cynics who say it’s a gimmick. But I am convinced that drinking water to help keep children and teachers hydrated during the school day makes a valuable contribution towards teaching and learning.

Heini Jones is head of the 25-pupil Ysgol Gynradd Gymunedol Dihewyd, Ceredigion