Well, I've never had to be in a situation like this. But what I would probably do is tell him what you feel his enclcosure setup should be. It sounds like he cares about his animals enough to listen to you; at least, I would hope so (with ALL those animals, he BETTER care!). So, basically, I would just tell him that if he doesn't keep heat on 24/7 it could give his bp an RI, and even kill him; etc. When you're explaining what you would change, explain WHY (how I just mentioned, "because it could KILL your bp"); so he doesn't think you're just trying to shove him around.

That's what I would try. Good luck, and if you confront him, let me know how it goes!
Jennifer