You'll often hear me telling you, "You're in charge", because you are ... when you're in my driving seat. Use any of the controls you need to help you do your job of driving the best you can: and yes, your comfort matters, 'cos any distraction (like being too hot or cold) will divert your concentration.
But what about driving examiners ? Who's in charge of them ? Well, it's the TCM (the Test Centre Manager). And here's what they do in a typical day.