I was camping in Big Sur in Northern California in November and brought my under quilt zero degree and top quilt with the Winter Barrier top shield. On the first night, I didnt install the top shield and it was windy. The UQ did a great job blocking the wind but I noticed that when the wind would go over the hammock from the top, it would pull a lot of heat from me. The first night was a bit chilly. On the second night I installed the top shield and did an excellent job blocking the wind. I was nice and toasty that night with no issues. Even if its not "winter" or zero degrees, the top shield does a great job in heat retention and even a bit more privacy when you hang. I am so glad I brought it and it packs down into a small form factor. Well worth the money and a necessary accessory for your Ninox.