Kerry,

I've had and old, wisened (and decrepit) starter "remaner" tell and show me
on the '84 SD's starter the incredible carbon buildup over 20 years of use.
Then he blew out the components (and bead blasted one or two) , reassembled
and said,"No new parts...Well not for another 200k miles".
Heat affects all the built up carbon , which acts as an insulator.

So, The inverse is also correct.
Cold "Shrinks" the heavily carbonized contacts away from each other,just
enough to reduce electrical transmission across the gap between the
contacts(until they "Warm Up" enough) to close the gap.

I think I am going to take this with a does of Buckminsterfullerines... ( one of the seven allotropes of carbon ) ... I am glad they did not know that carbon acts as an insulater when they put those carbon brushes into your starter.....