I have been to 19 F, with medium weight underwear drawers, lightweight t-shirt with a fleece pullover, a wool skull cap, and an Arrowhead Owyhee winter weight top quilt. I was completely comfortable, even to the point of having to uncover my arms at times. I had a few items in the pockets, but minimal. I hope this helps, I am still testing out various cobinations of nothing but pockets, Z-Liners, Z-liners with UQ (somewhere around 2 degrees), and I still don't have a standard go-to formula. I tend to lean toward a little extra insulation rather than minimal. I can always cool off (we're talking high altitude Colorado cool to chilly nights here), but cold butt syndrome is not my cup of tea.