youd think that, but no, as a vacuum there is actually very little heat transfer in space, its like the vacuum chamber in a thermos, keeps hot stuff hot and cold stuff cold
as i understand it the very cold effects actually come from water instantly evaporating in the low (zero) air pressure and IIRC the main concern with astronauts on the moon mission was overheating due to the difficulty in venting heat from the suits
No, this isn't right. Space is actually cold.
It is closer to a thermos bottle, true. Since there is no air or anything else, heat is not lost through the usual process of convection -- or in other words, there is no "wind chill" factor in space. But you can still lose heat through blackbody radiation. This is slower, but it still works.
In the thermos bottle, there's no air but the blackbody environment is at the temperature of the thermos' walls. If your thermos is at room temperature, say 300 K, then there's a 300 K blackbody spectrum of emitted light bouncing around inside the bottle. The spectrum thrown off by your food is at a much higher temperature, and thus gives off energy that is absorbed by the outer thermos bottle, giving you a net cooling. The cooling stops when the interior and exterior walls reach the same temperature. A really good thermos bottle tries to limit this effect with low-emissivity coatings, but you can't reduce it to zero, so eventually your soup will get cold.
In space, the thermos bottle is at the
interstellar background temperature -- 6 K or less. There's no mass in space, but there is a constant bath of photons, and this corresponds to a low temperature -- hence, space is cold. So basically whatever energy you radiate is just plain gone, and you get almost nothing back from the outside. You cool faster. Again, we use low-emissivity coatings extensively, like gold foil, but radiative losses are serious.
In Earth orbit or similar, you are warmed by the sun, on the side facing the sun. Again, reflective, low-emissivity materials help deal with the thermal load. But it is possible, therefore, to be both too hot and too cold at the same time. Many spacecraft spin as they travel in order to try to even this out, something we call "rotisserie mode."
On the Moon you have a different problem. Any point on the Moon gets 14 days of uninterrupted daylight (with sun bouncing off the ground around you as well) followed by 14 days of darkness. In the sun you get pretty warm, but at night it gets
nasty cold. Lunar equipment that you want to survive the lunar night needs its own heaters, and typically what we do is pack them with Pu-238 to keep them alive. This is a major concern for a sustained human presence on the Moon.