For cold therapy, place the packs in the freezer for at least two hours before use. Place them in the soft covers and apply to the affected breast for up to 20 minutes to relieve swelling, pain, and discomfort. For hot therapy, microwave each pack separately for 15 seconds, and test the temperature before use. Apply to the breast for up to 20 minutes to relieve plugged ducts, mastitis, or to stimulate milk let-down during pumping. Always use with the soft covers to prevent direct contact with skin.