Preventing Hibernation In Russian Tortoise?

We just bought our new today and brought him home and i don't want him to hibernate because of the health risk associated with it, can anybody tell me how to prevent him from going into hibernation and any extra tips to help him adjust to his new place. He is eating but only the spinach and ignores the grape tomatoes so at least hes eating, but now he just sits under his log and hasn't come out in the past 8 hrs