Can you iron money, or will it set fire? ...
Answers: As most of these answerers don't seem to know, the money is made from a majority of cloth. The paper myth is untrue.
Use as low a setting as you can unti it works. As far as unofficial, I don't believe they have Secret Service agents on standby outside everyone's houses for this sort of piece.
Plastic? No! Paper? No! Fabric? Yes!
Iron away!
Money is made of plastic and paper, neither resembling heat - it will most credible melt and stick to your iron...