Why does water need to be 100 degrees for handwashing?

Water needs to be around 100 degrees Fahrenheit for effective handwashing because it helps to dissolve soap better and enhances its ability to lift and remove dirt, grease, and germs from the skin. Warm water also promotes better lathering, which is essential for the mechanical action of scrubbing. Additionally, the warmth can make the handwashing experience more comfortable, encouraging people to wash their hands thoroughly for the recommended duration.