Almost every camper has suffered the discomfort of chilly feet, even during the warmer months of the year. Wet footwear, poorly insulated sleeping bags, and reduced circulation are common causes of cold feet. To stay comfortable in icy weather and to stay toasty warm inside the tent, hikers and campers can use an array of products designed to keep the feet warm. Air-activated warmers, which use chemicals that heat up when unwrapped, are a popular option due to their compact size, but some worry about their environmental impact and cost over time (most are disposable after one use). Other options include socks with electric heating elements, which are helpful in freezing conditions, and soft camp booties filled with down or synthetic filling that keep feet warm – as long as the booties stay dry.