I just set mine up a few weeks ago. The cardboard boxes worked well last year so I saved good sized boxes for it this time.
2 heat mats under the lower box, temps of both boxes stay above 65 or so it seems, even in the chilly back room of the garage.
The lights are those Walmart cheapies too, they work nice. Really disorienting to look at tho, so the closed boxes help with that and heat as well.
