Hand-washing: Do's and don'ts - Mayo Clinic
Wet your hands with clean, running water — either warm or cold. Apply soap and lather well. Rub your hands vigorously for at least 20 seconds. Remember to scrub all surfaces, including the backs of your hands, wrists, between your fingers and under your fingernails. Rinse well. Dry your hands with a clean towel or air-dry them.