Well, yes, some of us do, living in climates that get that sort of heat routinely.
Wait until it starts expanding into little hummocks and dips in the heat.
Yeah, we get that too, sometimes. And in the winter they shrink up from the cold and pull apart. Nuisance.
In my area of North America we routinely get multi-day stretchs of 90-100 degree heat in the summer, and have even hit an all-time high of 106 (that was beastly) It’s such a lovely contrast to the mid-winter -20 to -30. Really. Everyone around here owns three wardrobes - “barely there” for summer, “normal” for fall and spring, and “spacesuit” for the depths of winter.
But seriously, part of Britain’s problem is you aren’t accustomed to this heat. I’m sure your architecture is designed more to hold heat in than to allow free-flowing breezes. The lack of air conditioning and even fans in some cases has been noted. You’re probably not accustomed to dressing for this heat, or all the myriad little coping skills other people have.
Here are my suggestions:
Keep as much airflow in your living quarters as possible - open windows, obtain fans, etc.
Take a shower before bed. In my case, I keep my long hair wet, but if you haven’t got long hair drape a damp towel over your head and forehead. If you can direct a fan over it even better - you’ll dump a lot of heat that way.
Drink lots and lots of fluid - water, juice, etc. but go easy on anything with caffeine or alcohol since those two make you loose water faster.
Eat light. Small meals - your appetite is probably suffering anyway.
Move slower. Aggravating until you get used to it, but don’t force yourself to walk as fast as you do in cooler weather.
Find cool places. A half an hour out of the heat can do wonders.
If you get dizzy, have a pounding headache, feel lightheaded, etc. get out of the heat and/or seek medical attention. ESPECIALLY if you become very heated AND stop sweating seek medical attention - you’re either dangerously dehydrated, getting heatstroke, or both. Don’t mess around with that.