Creams are mixtures of oils or fats with water. Since water and oils are not miscible, it is necessary to add an emulsifying agent that avoids their separation. Creams are therefore stable emulsions of oils or fats. Medicinal properties are added to creams when they use or are made with tinctures, infusions, oil infusions, essential oils or decoctions. Creams are permeable allowing the skin to breathe and sweat. Their water content and some additional hydrophobic agent like Glycerin promotes the hydration and cooling of the skin.