at the point where he reaches his hand up under the hood to his mouth to warm it with his breath--I knew it wasn't an 'isolation suit' even when I was a kid.
Then you were better than I was. Incidentally, he did not put his hand up to his face to warm it. Tormolen took the glove off in the first place to rub an itchy nose. (How many people take off a winter glove to rub an itchy nose? To me, that further suggested the sort of isolation zones, as practiced in surgery.) Later he sticks his hand up to smell it after the organism leaps onto his hand. We can even hear the sniffing, and he checks both sides of his hand—not merely breathing on the side that touched the frozen console.
But we're agreed that the original intent of the script and the execution are out of synch.
Would the outpost interior be covered with frost? Maybe. It's not stated anywhere that Psi 2000's atmosphere is not breathable. If the station was hermetically sealed, then there might still be frost, as the moisture in the air condensed, but the frost would not have been so heavy... unless steam from some source (such as the shower, where Tormolen found someone fully clothed) added to the humidity in the air.