The building component of the Spacefarer Input/Output Ports don't track the temperature of their backing material:
This is mostly an annoying graphical bug, but on save/reload the temperature of the steel tile behind the building is reset to 20C as well. That can delete significant amounts of heat. Letting you do silly things like regulating a rocket's temperature by saving/reloading repeatedly.
1. Heat or cool rocket liquid or gas ports.
2. Reload game.