Baby or adult? I like to keep babies a little warmer.
As a species they can tolerate a wide variety of temps. You are likely to get a variety of answers to your question and none of them are necessarily wrong.
Well....if your tortoise is an adult and he/she is in an inside enclosure, it needs to be large enough to accommodate a variety of temps.
They need to get warm, when they want, with a basking area of 95f. They also need the option of cooling off with an opposite cool side of 65-70f.
They don't need heat over night in most homes.
They need a large enclosure.
Tell us more about your set up, and perhaps we can give you more information.