Our turn to bring the class hamster home this weekend

Son's class keeps a hamster, and each family takes it home for one weekend by rotation. Ours is this Saturday. He's thrilled. We live in a flat, have never kept any animal, and the instruction sheet is one page that mostly says 'do not let it escape'. If you've done this, what went wrong? I'm thinking about the AC, whether the cage can sit near a window in this rain, and the neighbour's cat that walks along our balcony ledge. Also, is a little report expected when it goes back? The last family apparently sent photos and a drawing, and now I feel we have to match it.