A method of cosmetically treating a superficial area of mammalian skin by irradiating the skin with a source of divergent electromagnetic radiation of between 900 nm to 1500 nm, and use of electromagnetic radiation of specified wavelengths. The cosmetic treatment includes reducing or alleviating or removing or diminishing wrinkles or fine lines, rejuvenating skin, retarding or reversing visible signs of aging, improving skin elasticity, tone, texture and appearance and beautifying facial, breast, arm, buttock, thigh, stomach or neck skin.
