[nudephil (OP)]

Biggi sent us this question:

Does using warm water when washing your hands make an actual difference, or is it because you are less likely to spend the requisite time when washing with cold water?

Is this an open question?

[Bored chemist]

It does a better job of dissolving the soap and I'm fairly sure it also does a better job of reducing the surface tension- which promotes better cleaning.