I still bike as long as highs are at least 25. Below that is just too cold. I wear a long-sleeve mock turtleneck from UnderArmour under a sweatshirt with thicker warm-up pants. I wear a face mask that goes from my neck to my cheekbones and wraps around my head covering my ears. I wear mittens on my hands. After 35 minutes/8 miles, my toes are a bit cold but that's it. If it gets above 35, I'll leave the sweatshirt off. Above 45 and I leave off the facemask. The high today was 17 with gusty winds, so I drove in.