Good Riddles

Question: When it's warm it has something warming it, but when it's cold it's naked. What is it?

Question: Imagine that you enter a room, but the door shuts behind you and you are locked inside. The room is 3 meters high, and 6 meters x 6 meters as a square form. It is dark, the floor is metal just like the walls and the ceiling. You cannot destroy the walls, ceiling, floor or door. How to you get out?

Question: Occurring once in a hundred years and once in thousands. But never in a day or a year or a century.

Question: Nathan has math 4 times a week. If he has math 8:00 Monday, 9:20 on Tuesday, 10:40 on Wednesday, and 1:20 on Friday, when does Nathan have math on Thursday?

Question: Having one, means having something to follow. Once you question it, it means having none. People seek it, but some do and some don't find it. What is it?