I think the whole cold weather thing is bunk anyway, unless its just snowing like crazy then both teams are affected equally (See the Buffalo Bills game last Sunday night). Now, if you are talking temps below zero, I am sorry but no one gets used to that and if you are playing football, rudimentary 30's is not a huge deal and actually feels okay with all the gear. Just keep the QB's hands warm.
Now, the same gear when the heat index is over 100F, THAT takes conditioning.
Now, the same gear when the heat index is over 100F, THAT takes conditioning.