What temperature should water be at when washing hands?

The appropriate temperature for washing hands should be at least 100 degrees Fahrenheit. This temperature ensures that the water is warm enough to effectively remove grease, dirt, and pathogens from the skin. Warm water helps to loosen any debris and makes it easier to lather soap, which is essential for effective handwashing. When combined with soap, warm water facilitates better emulsification of oils and dirt, leading to a more thorough cleansing of the hands.

Using water that is too hot, such as temperatures over 100 degrees, can potentially cause skin irritation or burns, which is why it's important to keep the temperature at a comfortable level for thorough washing without discomfort. Handwashing should be conducted for at least 20 seconds, regardless of the water temperature, to ensure effective sanitization.