I don't use heat at night, but have a little heat pad under one corner just in case I need to turn it on. I've been letting it get down to 67-70 at night because I literally have never seen her out and about unless it's dark and 70-71F. It's 69 on the cool side and she was just out climbing around on that side, soaking in her bowl and watching me for the past hour or so. I've never heard of a snake liking temps this low, so I assume it's more of a lighting thing and just switched over to a 60W CHE. We'll see what happens tomorrow.