Great for backcountry trekking and emergency preparedness, this package of four disposable foot warmers from Coghlan"s warms feet in shoes or boots for up to 4 hours. Easy to use, they"re air-activated and are safe and odorless. Coghlan"s makes the outdoors more comfortable and enjoyable with over 450 accessories for camping, hiking, fishing, and RVing -- from cooking gear to first aid kits, insect netting, firestarters, tent repair, and more.