How warm does water have to be to get bacteria off your hands?
A: Turns out cold water is just as effective as warm water, whereas using soap is the much more important factor. What’s more, using warm water costs a lot economically and environmentally. In fact, some estimates suggest that heating the water puts as much carbon dioxide into the atmosphere as 250,000 cars. Additional factors in effective hand washing are duration of time spent washing and amount of soap being used. The referenced study performed at Rutgers University found that 30 seconds of lathering with 0.5cc with plain soap is most effective. Using more plain soap, antibacterial soap, or washing for longer made no difference in the number of bacteria on the subjects’ hands.
References: Rutgers Study
Courtesy of Barbell Medince