A design flaw makes this a lot less effective in keeping you warm. The winters are long and cold on the high desert so dressing warm is a lot better than what it costs to heat the house. It's thin, soft and warm but the neck opening is way too large and even some of my shoulder is exposed. When my neck or feet are cold the rest of my body is cold and I have to wear something with a tight neck for this top to be effective. It just feels like I'm leaking heat around my neck. It's nice to sleep in but I'd prefer something tighter around the neck and would not purchase this again.