Lots of people carry on their person some kind of miniature bottle of hand sanitizer, while others use it from public bathrooms or from dispensers at public locations.
Hand sanitizer is a common fast alternative to washing hands when there's no soap and water around, so it's no surprise that lots of people use it. It can help fry germs on the spot within about 20 seconds, but studies have shown its weaknesses too.
Most good hand sanitizers are around 70% alcohol, which is the most effective at killing germs. On the other hand, different hand sanitizer types can be non-alcoholic, and these tend to be far less effective. Some studies even suggest that they can help bacteria develop antibiotic resistance, which means users of these hand sanitizers could, in theory, be helping bugs to evolve to survive current forms of treatment (again, unconfirmed).
Scientists do appear to agree that washing your hands with soap and water is more effective than using hand sanitizer, because this process not only kills germs, but it washes them away, unlike using hand sanitizer, which only kills germs.
Moreover, you can use cold water to wash your hands, because the "warm water only" wives' tale is very unimportant. Hot water only kills germs when it exceeds 99.98º Fahrenheit, which is too hot to wash your hands with. It would burn you. That said, just use cold water and some good soap.
Oh, and while we're on the topic of "good soap," it turns out non-antibacterial soap is just as good as antibacterial soap. So just use what you have, as long as it's soap. Soap has detergents in it, and all soaps clean things, like hands. So don't over-spend for specialty soaps if you don't have to.
