I wear Injinji toe socks almost exclusively for running and my gym workouts (which includes treadmill running). I have hammertoes, so the toe socks prevent my curled down toes from rubbing and irritating each other. When I have tried to wear regular socks for running, my toes almost instantly become tingly and numb...with the toe socks, this problem is all but eliminated. However, on days when I run outside in the cold...the toe socks just don't seem to cut it as far as keeping my feet/toes warm. They are a fairly thin sock...plus with the toes being separated in their individual toe pockets, the warmth factor goes down even more. I've tried the Nuwool version of them, too...still not warm enough for me. I need to find a viable solution that allows me to wear the Injinji socks, yet still provide enough warmth so that my toes don't freeze. About the only option I've come up with is wearing the toe socks like normal, and then wearing a pair of regular socks ON TOP of them. Would this work? Has anyone tried this combo with success? And yes, I already have covered my running shoes with duct tape to block out the cold air....in case anyone was going to ask.