Yeah, us Brits struggle with the heat. I can't speak for everyone but personally, I've been pretty miserable for the past fortnight or so.
My room gets very very hot, and the sun beats down on my window most of the day. It's like an oven, even my ceiling and walls are warm to the touch. I've been drinking lots of water and walking around in shorts but the nights are the main problem for me and most people. There's just no escaping it.
I understand why people are surprised we're fairing so poorly with the weather, more so due to the fact they live in even hotter areas with no problem, but the fact is, we're just not used to this heat, or at least this consistent heat. It's the longest heat wave we've had in 7 years, we just don't get weather like this.
The people perishing are the old and vulnerable for the most part. They're obviously not as hardcore as you.