There's actually truth to that. In a vacuum, heat doesn't convect and can only radiate away. Assuming all systems aren't down, then you're more likely to roast than freeze from all the heat from other equipment and such building up.
I've had a few old cars where you had to turn off the AC in order to accelerate fast enough to use a highway on-ramp. presumably if you get a lemon of a starship off craigslist, you need to disable life support to go to warp