I don't have great circulation and my hands (and toes) are always cold skiing, no matter what I do. I finally ordered these after reading so many positive reviews, and I wore them skiing in Jackson Hole when the temps were between -11 and 4. I added my own thin glove liners since this mitten doesn't come with any (which is fine). I'm happy to report the mittens worked wonderfully and I only got a tiny bit cold, which is amazing compared to normal. If you're going to go in temps even colder than the negative single digits, I'd recommend going with the Marmot Expedition Mitt, which is one step up on the heat scale. (But those things are super super bulky--they're meant for, like, antarctic expeditions.) All in all, I'm way pleased with this purchase and this will be my go-to ski mitten for very cold days at the resort and in the backcountry. I like keeping glove liners on underneath so I can easily slip the mittens off to fiddle with my boot buckles, phone, etc.