I used to LOVE hot weather and was rarely affected by it. I spent a year in Australia and worked outdoors/in non-air-conditioned farm buildings in high 30s/40s and was fine.
It's about mid 20s here and I'm sweating, hot and irritable. And have been for a few weeks. We're booked to go to Corfu at the end of August - I'm going to actually melt, I think.
It's my age isn't it? (Early 40s). 