It's clear and cold again, when I left for work this morning the rooftops were frosted white. Frost always takes me back to childhood. When there was a heavy or hoarfrost, I would go out before school to slide down the field opposite our house on a tray. Sledging on frost felt more risky, edgy, than on snow – the frozen ground could easily inflict bruises. It was also a sport no one else seemed interested in, so I had the field to myself – bold and alone.