Yesterday I ran to work and back in -10c / 15f with a wind blowing of around 20mph increasing the wind chill. Sure it was VERY cold and I could have easily ran indoors on the treadmill. However, I didn't have the car to drive to work, and with the increase in wind chill and length of time to change into cycling gear running was the best option, and warmest! My time in the army many years ago taught me about prior, proper, preparation, prevents piss poor performance. With this