UGG Boots Classic Short are exceptionally warm and are great for cold weather. Don't miss our UGG boots sale clearance. Avoid fabric conditioners, washing powders, detergents used for laundry or anything containing enzyme. The natural insulative properties of sheepskin gives thermostatic properties to the boots: the thick fleecy fibers on the inner part of the boots wick moisture and allow air to circulate, keeping the feet at body temperature.