(Also cold? An actual spaceship? Have you heard how difficult it is to cool these things off?)
Given that I wrote
a giant post here once talking about how Flux was basically heat-by-another-name... yes?
As for practical effects... in the real world, it depends on what part of the ship and a bunch of other factors. Spacecraft are not exactly radiating evenly; some parts will be quite cold and some are quite hot. Depends on a bunch of things. It's more accurate to say that "space is really cold, but parts inside a spacecraft may have major problems with heat distribution and buildup because of the problems with heat transfer in zero G".
The Atomic Spaceship guys are down on lasers, and that's a consistent theme.
But... their assumptions are weird.
They throw out the word "diffraction" and don't really explore what's possible in regards to collimated beams. Essentially, a laser weapon could, in theory, adjust the point of least diffraction dynamically, based on the target's current distance from the target; this is much of the theory behind current laser weapons research using LED arrays- not just pushing out sheer power, but making the power arrive really efficiently at the target point, so that you aren't wasting energy defeating thermal bloom, etc., quite as much.
Their other big assumption has to do with effects of rapid vaporization on structures due to lasers or other high-energy beams.
There isn't lots of research available to the general public on this, but, based on my practical experience, I can tell you that a beam that doesn't blow through an armor plate will do pretty unexpected (and violent) things to it, at least in an atmosphere.
The most dangerous part of cutting thick steels (we cut up to 1 1/2" Hot-Rolled P&O steel, which is a pretty mild steel with relatively low reflectivity) was the initial piercing of the steel, where chunks of steel might shatter out and blow all over the place, leaving a dent in the plate that looked like somebody had shot it with a bullet; heat stress shearing was real problem.
We had to compensate by programming in a slow pierce cycle, where we basically cycled the laser on and off about every tenth of a second and blew oxygen out, resulting in a pierce time of about 15 seconds, if we wanted to minimize blowouts. When we were first doing test-cuts on that material, we blew out chunks of red-hot steel with quite-audible "bangs", fountains of sparks, and you could feel the vibrations through the enormous mass of the plate.
And this was a late-1980's tech, giant inefficient laser that was relatively low-wattage and wasn't designed for a military use at all, that was being used on a material that wasn't even officially within spec (official spec, IIRC, was 3/4" HR P&O; we were cutting double that).
So, while I certainly haven't worked for any military designing laser weapons, I feel pretty confident in saying that, while there are problems, they aren't what the Atomic Rocket guys think they are. But hey, just view this and tell me laser weapons don't work... does that look like gentle, "micrometers/second" or more like what I'm talking about?
https://www.youtube.com/watch?v=tyUh_xSjvXQ