The temperature affect on running in the cold will affect the warmth and flexibility of the muscles in the legs and arms making an injury more likely if the muscles are stretched quickly. When running in the cold the runner should pay attention to several factors.
Clothing: Run with a hat to retain heat in your body. No worries about hat head – just keep your body warm. Use layered clothing to provide the best warmth possible. Look for material that will wick moisture away from your body allowing it to evaporate. Your outer layer should be gor-tex to allow for evaporation of sweat and will allow you to stay warmer.
Decrease your outdoor running schedule: cold weather will negatively impact your immune system. Try to incorporate more treadmill running and halve your outdoor running schedule until the weather warms a bit.