All the comments about 'thirst' here remind me that once one is thirsty, that's the first sign of dehydration. Steadily drinking more water than normal during hot weather is probably a good habit to adopt. In my garden today the thermometer reads 36 in the shade - and that's now at 7.10pm. Anything outside that is not done before 8.30am, we don't bother with. Had sunstroke once, years ago. Not very nice. Now I'm old and a lot more sensible, I stay out of the heat during the hottest parts of the day and, like the bats, come out at night! 🦇