You can simulate rain in practice if you're going to play in the wet stuff, but as for preparing the cold? That's a lot harder for NFL teams if you don't live in a very cold place. But the New Orleans Saints are playing cold-weather chess,

The Saints appeared to be on the verge of snapping the shutout late in the first half, driving from their own 39-yard line to the Packers’ 29. But on second down, Rattler was sacked by blitzing cornerback Keisean Nixon, who forced and recovered a fumble by Rattler for the first turnover of the night.