ONI keeps going in the wrong direction. Constantly taking the input of the "exploit" crowd trying to make everything more tedious and boring by only having one "right" way to play. It doesn't become more difficult - just so much more tedious to have to micromanage one more step (freezing), and it limits even more the kind of interesting bases you can build as you have to follow yet another rule limiting your creativity. I love this game. I've played over 1000 hours in it according to my Steam profile, but it has gone steeply downhill the past 6 months as I increasingly find it's just a grind to adjust my playing to yet another "exploit" being "fixed" and forcing me to play the way someone else wants instead of what I want.
Using vacuum as an insulator I've found that gas randomly gets into my vacuum. It's been happening in the save at random times - reloading the last cycle and replaying it would change the outcome and my vacuum would not be compromised. However, I finally got a reproducible savegame - note the little bit of gas(CO2)/heat in the upper right corner, that's where it shows up every time, and in this save it triggers when my dupe opens the inner door to the power unit. I reloaded the save 5 times getting the exact same result - probably because the dupe already had a target inside the power unit so he will enter at the exact same time each reload. If I manually move him somewhere else - and then inside the power unit no gas are created in the vacuum, so it's clearly related to his entering through the door. I hope this can help explain what is happening. GasBugSave.sav