Washing is a method of cleaning, usually with water and often some kind of soap or detergent. Washing both body and clothing is an essential part of good hygiene and health. Often people use soaps and detergents to assist in the emulsification of oils and dirt particles so they can be washed away. The soap can be applied directly, or with the aid of a washcloth. People wash themselves, or bathe periodically. Infants, the sick, and people with disabilities are bathed by a caregiver, but those that can wash themselves often do so. Often a shower or a bathtub is used for washing. People bathe naked under most circumstances, and commonly do so in the privacy of their home. In Europe, some people use a bidet to wash their external genitalia after using the toilet, as opposed to using toilet paper. More frequent is washing of just the hands, e.g. before and after preparing food and eating, after using the toilet, after handling something dirty, etc. Hand washing is important in reducing the spread of germs. also common is washing the face, which is done after waking up, or to keep oneself cool during the day. Brushing one's teeth is also essential for hygiene and is a part of washing. 'Washing' can also refer to the washing of clothing or other cloth items, like bed sheets, whether by hand or with a washing machine. It can also refer to washing one's car, by lathering the exterior with car soap, then rinsing it off with a hose, or washing cookware. Excessive washing may damage the hair or cause rough skin or skin lesions.