Ah, I wasn't sure what was going on there, logistically.
To keep it on topic I think the idea that players "heat up" as the weather does and players from warmer climates struggle in the cold is probably bogus too, so long as they are properly prepared by the training and equipment staff. And it's also an "affects both teams" situation.
Connor Brogdon pitched in Idaho so that logic would also make him the Phillies' best reliever on a cold night. Mick Abel doesn't see much winter but he's used to rain and 40 degrees.