Football in the Cold

Bodies subjected to extremely cold temperatures will shift into survival mode.
To keep the body warm, and organs functioning, blood is kept closer to the heart instead of legs, arms, hands, and feet. This can cause a decrease in reaction time, frostbite and even hypothermia.
Cold, dry air can irritate the respiratory system, making it harder for players to breathe and catch their breath after running plays.
The cold weather also causes muscles to be less able to stretch.
Dehydration is also possible in cold conditions as players are sweating underneath their clothing and equipment.