How much does the cold affect the cnc router

[EddyCurrent]

About 142 miles North of me, my shed got to 8C (outside -2) but I have a dehumidified going to keep my timber stock at the right moisture level.
I read somewhere that aluminium expands about twice as much as steel for the same temperature rise. Also what type of heater are you using ? if gas then this puts out a lot of water and might be affecting the MDF which is like a sponge. I'm trying to imagine the expansion of a cnc machine and it's like the expanding universe, where is the centre of expansion ? and how does this affect the tool position. I would not have thought the 6 degree rise would have given a visible difference but I suppose local heating will be greater as the stepper motors and spindle motor heat up so maybe you should run some random G code for a while just to heat things up before starting to cut.