
The island is scattered with hundreds of German fortifications built while it was occupied during World War Two.
The children had since been "nipping down" for short cool-off periods, said Judd, with a lesson also taking place in the unusual setting.
She said a Year 5 teacher had suggested the footbath idea and the children "just love it" with one saying it was the "best day in Year 5 ever".
Judd said: "I mean, we've taken them on French residentials, we've given them so many experiences, but sticking your feet in a bucket of water is obviously the best thing ever!"
Beatrix, nine, said of the footbaths: "It's better to keep cool when I'm working and it makes me concentrate more."
Anna, 10, added: "It's a bit strange when someone says 'we're going to put our feet cold water' - but it has helped."
Harry, 10, said the footbaths were "helping a lot", while Ava, 10, said she was pleased they were also allowed to bring fans to school.
