Our understanding of the seasonal cycle at higher latitudes, with its annual oscillation in temperature and sun hours, owes a great deal to the development of controlled fire. It was a knowledge of this technology, along with advances in body insulation, that permitted early hominids to push into new territories where temperatures varied greatly between the seasons, and where the cold of winter would have precluded human survival had it not been for artificial heating and heat preservation. By moving away from the equator, our ancestors effectively created a new enemy for themselves in the shape of the winter season. At this time of year more than any other, their survival in moderate and subarctic zones depended on technology, a shared and therefore social acquisition that has left a more profound mark on the genus of homo than anything else has. With it, humankind learned to shut out the world outside and create a space of its own.

Energy infrastructure has undergone dramatic developments since the taming of fire. Consequently, developed societies today enjoy the most seasonally uniform lifestyle in the history of human life outside the tropics. Architectural developments, the exploitation of new sources of heat, and ever-improving insulation technologies are only a few facets of this feat. In some of our cities with their year-round climate control, heated parking garages, and seamless underground transportation infrastructure – winter cities, as Adam Gopnik calls them – it is now possible to avoid direct contact with the elements altogether if one so chooses. Meanwhile, the airlifting of produce has done away with seasonal limitations on the availability of virtually any food while vastly expanding the dietary range available to us. On an existential level, therefore, the cycle of the seasons has lost much of its immediacy for those with access to advanced infrastructure. What remains of our susceptibility to the seasons largely belongs to such domains as mood and leisure: cultural and psychological responses to a material reality.

This book concerns such responses to the seasons, but it looks for them in the medieval literatures of England and Scandinavia, whose authors could not so easily dismiss seasonal variation as a matter of November gloom and February skiing. Even after coal heating and the chimney became more widely used in the thirteenth century, the seasonal experience remained one of considerably greater exposure than is typical of post-industrial societies.