Yeah, it's definitely looking like I need to get him an additional heat source for winter. Thanks for the suggestions, guys.

I'm looking at CHE's right now, but I'm wondering whether an infrared light would do the same trick in terms of providing him extra heat? I don't know why the CHE is so expensive lol, the infrared is more affordable, to my understanding the only difference is that the infrared does also emit a light but the CHE does not, the function should still be similar?