Summary: How Cold is too cold to Run Outside?

So where do I draw my line for cold weather running?  If it’s single digits, or below I move it indoors. Remember, I’m talking actual temp, not “feels like” or “wind-chill” temps. Those things shouldn’t matter too much as long as you cover your skin and dress appropriately. Could I get away with exercising outside when it’s zero, or even -5 degrees without ill effects? Probably. 

https://ultraversesupplements.com/too-cold-to-run-outside