Herbal Heat Packs with Lavender are a safe, environmentally friendly, natural means of pain relief. Soft and pliable they can be used hot or cold. Simply heat for up to 90 seconds please DO NOT OVERHEAT the PRODUCT, in a microwave or chill in a freezer then apply the soft pliable wheat bags to the affected area. When used hot they can be used for Arthritis and Aching Joints, Sprains and Strains, Menstrual Pains and to aid sleep and stress. Use frozen to reduce fevers, swelling, bruising, sports injuries and sunburn relief.