Maximum working temperature

I spent the afternoon in a small windowless office with the thermometer reading just over 90F.
Unfortunately there is no legal maximum working temperature in Britain... (but I did get offered an free ice lolly!)

Edit: I've just come in sweating from cycling in my shirtsleeves at 11pm -- it's as warm as a summer's day out there. I'm afraid this will stop the tomatoes dead in their tracks, since as we discovered last year they simply don't set when the nights are too hot.
Fortunately I think the towel-tomatoes have pretty much set a complete crop already. (And the first two fruits are definitely going orange now...)