Cold
After having been in England for just over a day, the first lesson I have derived from my many experiences is that One Should Not Sleep With A Window Open At Night. Imminent result: unavoidable and extreme frigidness. In other words: it's bloody cold.
I have it from good authority, nonetheless, that people in England do not generally wake up at 6.30 in the morning, and so have no conception of exactly how cold it is in the mornings; so I am in good company.
More later. Too cold.