No one bothered to bring her an additional blanket. It was entirely possible that he was angry enough that he wouldn't care if she died down there. Every person had their breaking point. Maybe Rodolphus finally found his. Without her beaded bag, she felt naked and exposed. Hermione wrapped the stolen cloak and the thin blanket as tightly around her body as she could in an effort to conserve as much of her body heat as possible. The temperatures dropped at some point in her stay. If she discovered that there was snow on the ground outside, she wouldn't have been surprised.