I can't go out in sub 20 weather without goggles...eyes tear up bad enough I can't see a thing. That said I've only gone out down to about 8-9F. Sub 20 degrees I can't keep my feet warm....that's the limiting factor for me. Feet are fine until about 30 minutes in...then they just get colder and more painful for the last 30 lol. I've tried double wool socks and 1000gram thinsulate boots. i suppose I could get those chemical heating packets for each trip.