The Hot&Fresh Warming Insole Camphor – Lavender (here insert images of oils and plants) Warming: The Hot&Fresh Warming membrane takes advantage of the properties of mineral salts and essential oils, including the properties of camphor and lavender, often used in cosmetics for the production of creams and ointments, for exercise preparation and against muscle contractions. These are substances that cause peripheral vasodilation; an increase in surface blood circulation. Thanks to Hot&Fresh technology, camphor and lavender can finally be used for the production of insoles and unlike other heating products, Hot&Fresh insoles do not require direct contact with the epidermis. They also give the feet and shoes a delicate scent.