That's... pretty much the only reason you need. No heat == cold. If you were asking why the poles are always aligned such that they don't point at the sun, http

That's... pretty much the only reason you need. No heat == cold. If you were asking why the poles are always aligned such that they don't point at the sun, https://www.quora.com/Why-do-most-planets-in-our-solar-system-have-poles-more-or-less-perpendicular-to-their-orbits https://www.quora.com/Why-do-most-planets-in-our-solar-syste...