Collard Lizard not feeling well...

Question
I have a 3 yr old female collard lizard, who seems lethargic, not moving around, eating or drinking and mostly sleeps, usually she's very active.   This has been going on for about a week. If she is not receiving enough UVB light or adequate heat, can she start to hibernate?  Is this possible? We live in Canada and last week was extremely cold and perhaps her tank was not  hot enough.  Do you have any suggestions or thoughts, I would be very sad to loose her.

Answer
Her set up would be similar in temp to the uromastyx, a true desrt lizard, and the collared lizard does brumate when the "weather" is too cold.  I would need to know your set up to see if the temps are cold enough for her to go into brumation, which makes her metabolism slow to a crawl.  She should not lose weight.  If you are worried, then of course the vet can be the best bet to rule out anything else medical.  I would still offer a little water every few weeks so she does not ddehydrate, but if she refuses, don't worry, she'll drink if she needs it.