So last year I picked up a 40 degree incubator and burrow from HG both with 2 ounce overfill. Been on a few camping trips, about 12 nights so far, and absolutely love these quilts. Two weekends ago i got the chance to see just how cold I could take these quilts down to. The first night the temps got down to right at 30 degrees with a slight breeze. Only woke up once in the night with a cold spot, readjusted, and good to go. Second night was slightly colder with wind chill down to 19. Didn't want to take a chance on being cold all night so i cheated and used a pad that night. Overall, really impressed with HG quality, and think i will be picking up a 20 degree set for next years winter season.