Most of England and honestly Europe doesn't have AC. Their homes are built to retain heat in winter, not shed heat in summer. So this entire situation is exacerbated. Here's some advice from a Texan who grew up in the swamps:
Darryl Mott
To translate this into American, London is projected to go over 100 degrees next week.
That had never happened anywhere in this country in recorded history until 2003.
Three years ago, we hit 40 C (104 F) for the first time ever; now, we might do it again.
And we're so not ready for it.