snaregirl

I read this book a couple of years ago and I think it's YA. It's about a girl trying to steal gold from a building with the help of her techy guy friend. In the end, the gold is actually on top of the building. I remember the girl had to coat herself with something cold so she couldn't be detected by security cameras. I also think the title had "heist" in it, but I'm not too sure. Thanks!