Tortoise trouble

[PlodsTempMum]

Hello all. My name is Amanda and I am the temporary Mum of a tortoise called Plod, who was landed on me when my Mother in Law decided that Australia was a fab place to spend three months.

Now please don't all shout at me because, until recently, the only experience I'd had with tortoises was vague memories of people having them in their gardens when I was a little girl (way back just around after the time of the really big reptiles). So I have only been following the instructions that my MIL left me before she went to Aus. But I am now worried about him and need some help, even more so after I started reading some websites about keeping tortoises and discovered that I am doing everything wrong.

Plod is about 18. He is a tortoise. If I can work out how to post photos on here then I will put one up but all I know is that he is a Mediterranean tortoise. He lives in the MIL's back garden mostly but free ranges around the house as he pleases. I was told to feed him mixed veg, greens, the odd bit of salad and maybe a bit of apple. I was also told that he doesn't hibernate. He may nod off for a few days at a time but no more. Whilst on holiday with us, MIL told us to keep him in the conservatory (which is unheated but gets very warm when the sun is out). He also has a house and run which we set up in the garden when he first arrived but it is too cold for him now. He is NOT free ranging around my house. I have a cat, a toddler and waaaaayyy too much in the way of PCs, cables and boxes with flashing lights (hubby is in IT) for him to be safe.

Sorry about the long post. Getting to the point - honest. Anyway, Plod has stopped eating. No idea whether to worry about this. No idea whether the conservatory is the best place for him. No idea whether to keep him cool so he'll sleep if he wants or keep him warm indoors. Found that Jackson ratio thing the other day and, going by that, he is underweight but not of low weight.

Does anyone have any advice for a complete novice as to where to go from here? I don't want to cause him any harm. Even though those beady eyes are getting to me...

Thank you.