Yup! Two! I use the hides from reptile basics and just ordered two more yesterday! For a three foot ball I think the medium would work well. My BP is 41 inches, about, but she's had the medium hide ever since I got her when she was 18-20 inches? You could just get a third hide and stuff that with moss, but a little plastic container is cheaper. And I'm curious, how are you measuring ambient temp, heat pad temp, and humidity?
I forgot to say, good for you for taking him in! I'm glad you took him in before he got sick or anything. Don't stress out about him too much, snakes are pretty hardy animals.
0.1 Super pastel