How is the sun still on fire when it's cold in outer space?

Answer 1

To start off, space is not necessarily cold. Conditions in space can be very hot near a hot object such as the sun. Second, the sun is not truly a fire, but a giant, natural thermonuclear reactor. The heat generate by the fusion of hydrogen into helium drives more fusion, which in turn generates more heat, so the sun sustains itself in this manner.