I'm not sure that I'll get the English terms wrong but basically heat can move in three ways:
By convection, aka liquids and gases moving around when theire heated. Obviously this doesn't happen in space
By conduction, a hot thing thouches a cold one and heat transfers from hot to cold. And, this neither works in space
By radiaton. Hot objects radiate heat as electro magnetic waves (ie ligth). This is the only one that works in a vacuum and this process is rather slow. Also this results I the weird phenomenon that good looking people cool down faster in space since their hoter. Therefore we should only recruit bad looking astronauts, but no one seems to have figured that out
And how did you take this one?