Adjust your focus
When you start to feel flustered you tend to think only on that sensation. Especially when you're in public you begin to think things like, "when they see me sweat for no reason they're going to think I'm weird!" or "I forgot to wear deodorant today and all this sweating is going to cause donut patches under my arms!" All this panicking is doing nothing but make you sweat even more, so all you have to do is change your focus. This might sound easier to say than actually do, but it's easier than most people think. For example try to think of all the cool air flowing through the air vents in the room. What better to focus on than what will keep you cool, right?
Fan Yourself
If you find yourself dripping in sweat and you absolutely cannot change your focus then simply find something to fan yourself with. A book or a stack of papers work very well to create that nice intermittent air flow to your face. Don't be afraid to fan yourself either. You might say, "If I fan myself people are going to think that I'm a girl." Listen, if you're worried about what other people think then you really have to practice on adjusting your focus. Remember....cool thoughts are the best....just listen to the hum of the air conditioner....let it fill your mind.