The C3PO costume can have a small fan placed near the back because of the metallic nature of the costume. The other costume that does have a fan in it because it is partially inflated is the Carnosaurus at Animal Kingdom. As a previous performer there, I never saw a fan in any other costume.
Now is the time. Now is the best time. Now is the best time of your life. Life is a prize. Live every minute. Open your eyes and watch how you win it. Yesterdays memories may sparkle and gleam. Tomorrow is still but a dream! Remember the past, but live for today. The whole world is watching and your in the parade. There's so much to cheer for, be glad you're here for it's the best time of your life!