It sounds absolute crackers, but I'm gonna say it anyway;
I used to subscribe to the notion that the heat abroad wasn't as insufferable as when its hot here in the UK. Then I spent seven days in Poland, Slovakia and the Czech Republic the other week! Literally never known heat like it, it was horrendous during the day, even the locals were complaining. Into the 40s, no breeze but air con in the hotel so all was not lost.
That said, to go from the heat in a most stunning part of Slovakia, to sitting on the top deck of the 10A coming home from work in this heat, kecks sticking to you, stuck in roadworks, bus smelling of wet dog and weed.......... hell on earth.