I drive a private hire vehicle with air con. and climate control (not bragging - nothing special, as a lot of cars now have it fitted as standard!) and I wish I had a quid for every passenger that gets in on a stinking hot day (we've just had one yesterday. 28 degrees, believe it or not, in the UK) and promptly opens a window, which then triggers my standard, pre-prepared script of: "I do have the air conditioning running and if a window is open, you'll let all the hot air in". Should have a recording of it really as I say it so often!. Kids are the worst. Cue whining voice........"I'm hot. I want the window open". I usually counter that with the remotely controlled child locks (also disables the window controls - cackle, cackle!) and this spiel: "Now, imagine you're sitting inside a fridge. You wouldn't leave the fridge door open, would you?", which normally works, especially if the parents cotton on and intervene. I distinctly remember one guy in the car with, I suspect, limited intelligence who insisted that: "That's all right, mate. It's cooler with the window open". Hmm. There's no real answer to that assertion. He was bigger than me. One person insisted on having the window cracked open a couple of inches the whole 60-odd miles during an airport trip on a hot day and there's always the odd passenger (VERY odd!) who "hates air-con". Doh!