I put my sisters hamster in a submarine bag?

I wanted to make a hamster submarine, so I took my sisters hamster and put him inside a plastic bag. Then I placed the bag in my aquarium and put a rock over the bag to weigh it down. After a few hours in his submarine, I opened Cocoas bag and saw that he was sleeping. He hasnt woken up yet, and I am a little worried. Will he be ok?