Russian tortoise not eating

[Garth turner]

My 6 month old Russian tortoise has stopped eating and pooping this last few weeks. When his lights come on in the morning he’ll come out of wherever he is sleeping walks about for about 30 mins or so sits under his lamp, then goes back into his bed. Sometimes he will come out again in the afternoon. His temps are 30-32 centigrade, and his humidity is between 40-60. I live in Northern Ireland U.K., so it’s starting to get colder. Is this sign of trying to hibernate?