Clothing is fiber and textile material worn on the body. The wearing of clothing is mostly restricted to human beings and is a feature of nearly all human societies. The amount and type of clothing worn depends on physical, social and geographic considerations. Some clothing types can be gender-specific, although this does not apply to cross dressers.
Physically, clothing serves many purposes: it can serve as protection from the elements, and can enhance safety during hazardous activities such as hiking and cooking. It protects the wearer from rough surfaces, rash-causing plants, insectbites, splinters, thorns and prickles by providing a barrier between the skin and the environment. Clothes can insulate against cold or hot conditions. Further, they can provide a hygienic barrier, keeping infectious and toxic materials away from the body. Clothing also provides protection from harmful UV radiation.
There is no easy way to determine when clothing was first developed, but some information has been inferred by studying lice. The body louse specifically lives in clothing, and diverge from head lice about 107,000 years ago, suggesting that clothing existed at that time. Another theory is that modern humans are the only survivors of several species of primates who may have worn clothes and that clothing may have been used as long ago as 650 thousand years ago. Other louse-based estimates put the introduction of clothing at around 42,000-72,000 BP. The primary function of clothing is to improve the comfort of the wearer. In hot climates, clothing provides protection from sunburn or wind damage, while in cold climates its thermal insulation properties are generally more important.