What could I wear to go as Abby Sciuto for halloween?

I have a few plans in mind already. I know I need a lab coat, a black wig of some sort, and gothic clothes; all of what I can find at a thrift store. Here's thing though. Where I live, it tends to get really cold around halloween, even getting snow on most years. What should I look for that keeps with the theme but won't have me freeze? Mini skirts are way too cold!|||As skirts you can wear a a mini skirt and have thick tights under or wear a longe shirt or like black pants. Go to a dollar store and get tattoos, maybe you can print of some spiderwebs and trace them on your skin! Go idea though!|||Don't go as that..