It can be said that there are four primary factors in clothing comfort, identifiable as the '4 Fs of Comfort' (1) fashion; (2) feel; (3) fit; and (4) function.^[2] In hot climates, clothing provides protection from sunburn or wind damage, while in cold climates its thermal insulation properties are generally more important. Shelter usually reduces the functional need for clothing. For example, coats, hats, gloves, shoes, socks, and other superficial layers are normally removed when entering a warm home, particularly if one is residing or sleeping there. Similarly, clothing has seasonal and regional aspects, so that thinner materials and fewer layers of clothing are generally worn in warmer seasons and regions than in colder ones.

Clothing protects people against many things that might injure the uncovered human body. Clothes act as protection from the elements, including rain, snow and wind and other weather conditions, as well as from the sun. However, if clothing is too sheer, thin, small, tight, etc., the protection effect is minimized. Clothes also reduce the level of risk during activity, such as work or sport. Clothing at times is worn as protection from specific environmental hazards, such as insects, noxious chemicals, weapons, and contact with abrasive substances. Conversely, clothing may protect the environment from the clothing wearer, as with doctors wearing medical scrubs.

Humans have shown extreme inventiveness in devising clothing solutions to environmental hazards. Some examples include: space suits, air conditioned clothing, armor,diving suits, swimsuits, bee-keeper gear, motorcycle leathers, high-visibility clothing, and other pieces of protective clothing. Meanwhile, the distinction between clothing and protective equipment is not always clear-cut, since clothes designed to be fashionable often have protective value and clothes designed for function often consider fashion in their design.