Well, what are the temperatures exactly? Snakes get ill very slowly consequently they heal slowly as well. If they are getting over a illness that may be the reason the appetite hasn't returned. As long as they have fresh water and you monitor the weight you could be on top of things. The specifics of the enclosure would help though.
The low side of her home is 76-78F and the high end is between 83-86F and right on top of her heating pad is 92-94F under the bedding.