Stay warm to and from dance class in these fashionable yet efficient warm-up booties. So Danca’s brand new warm-up booties keep your feet warm and comfortable, without the need to remove your ballet shoes. Warm-up boots retain heat and encourage the muscles to warm through. Made from waterproof nylon fabric, the BT-30 warm-up booties have a non-slip full sole and bungee fasteners for personal adjustment.