Yes, it's a factor... but no where NEAR, IMHO, how us fans think it is. You've played football, right? Anything down to 25º or so and you're going to be sweating your ass off. Maybe less than 25º
I would bet good money most football players would say the optimum temp for game is less than 50º. 50º down to 32º is great... 32º to maybe 15º perfectly manageable. (I'm just guessing, obviously, but my point is.... it's got to be liquid nitrogen cold before you're going to feel cold).
