No, it is not a good idea.
Temperatures in my part of southeast England hovered around 20 degrees. While this is not baking hot, it’s still a perfectly respectful summer temperature, for England. If we stop imagining that we are a Mediterranean island with unfortunately poor weather patterns and instead embrace the fact that we are a northerly nation, in line with Norway who get very few really hot days relative to the length of the yearl
It;s perfectly warm enough to stay in summer clothes, so o do that, before the temperature really does plummet.