Staying warm while downhill, Nordic, or backcountry skiing, snowshoeing, or hiking in winter is a constant challenge: We sweat, our clothes get damp, we have periods of reduced exertion like riding a ski lift or walking downhill, and then we get cold. But as humans have known for thousands of years, it’s a matter of smartly managing and insulating our body’s furnace (and today we have much better technical clothing than animal skins).
Clothing only helps trap heat; your body is what keeps you warm. Anytime you get cold, the single best strategy for rewarming is to start moving or increase your pace. Watch others in your group for signs that they’re cold, especially children, who have less body fat and mass and cool off more quickly than adults. When you take a break, make it short, to avoid cooling off. If someone has visibly cooled off faster than others during a break, have that person start moving ahead of the group; you will regroup before long.