This Halloween, I decided to be Alina Starkov from the Grisha Trilogy by Leigh Bardugo. In the books, she's the one and only Sun Summoner, doing magic with light and heat.
Since those powers were beyond me, I put together a set of Arduino-controlled gauntlets instead, that would light up on gesture commands and slip under my sleeves. [This set up, with a few tweaks, would probably serve you well for Iron Man, too]
Here's how I did it, and you can check out the gauntlets in action on Vine.
I wanted to work with sewable arduino components, so I bought within the LilyPad system. You could substitute out another arduino board, but then you'd wind up needed to solder, instead of sew. Here's what I got (for a set of two gauntlets, just halve for one):