I have a big setup with 4 Thermo-Regulator in a row, to cool down Hydrogen in order to cool down Polymer Press and other stuff, it means that Hydrogen lose 56°C when passing through the setup. So I know I can have really low temperature quickly.
When I loaded the save, the setup wasn't functioning anymore: the Hydrogen wasn't cooled down for less than -80°C. Each Thermo-Regulator refused to cool the gas under this temperature. The gas entered at roughly -60°C/-70°C so the first Thermo-Regulator cooled it down to -77.9°C, but the others didn't allowed it to go under this level.
I exited the game and launched it again, reloaded my save, and the Thermo-Regulators cooled the gas to less than 80°C again.
Also, that time when the "bug" happened wasn't the first time I loaded my save since the last game upgrade.
Start a save, the Thermo-Regulators will not function as intended. Reloading the save correct that. It seems quite random.