Your conditions: no hairdryer or portable heat sources (like a lamp), no working fans, and no way to get them close to the heat vents short of ducktaping them to the registers.
I had no idea how long they were soaking before I got home, so I squeezed as much water out as I could then set them out on a counter covered with paper towels. They're facedown at the moment, with the halves fanned apart as much as I felt they could go without ripping the weakened pages.
Because of where and how I storing them they're all books I've read before, so it's not urgent that they be recoverable. They all happen to be ones I'd like to reread at some point in the future, though, so any help is appreciated.