Kibber sits at more than 4,000 metres, above the Spiti river, with its houses built close together against the wind.

In the winter, when the fields are frozen and the road is often shut, a schoolteacher in the village runs evening classes for adults in the school's one heated room.

Most of the students are women who left school early. They learn to read and write Hindi and English, and to do the sums for the guesthouse accounts many of them now keep.

The class starts at five, after the animals are fed, and ends when the generator does.