[RubyO (OP)]

Rob has a curious question on his hands:

I was interested in what the ideal temperature was to wash your hands in. Assuming you washed your hands with soap, there are a couple of conflicting factors in my mind. We wash our hands to remove bugs essentially. Warm water feels nice and would help dissolve dirt/bugs and rinse them away and perhaps helps dries hands as well (evaporating the water, good to dry hands). Hot water would burn your hands, so that's no good. The main confliction I think is that warm water be a nicer temperature for bugs to grow on your hands. Colder water would discourage their growth. I think warmer water is the answer (as hot as you can handle). There are other factors like comfort, blood flow in your hands, health factors, that are also important apart from washing away bugs.

Can anyone clean this up for him?

[Bored chemist]

I suspect that the dominant factor is that most people don't take long enough over washing their hands to do it properly.
Water that's not at a comfortable temperature is going to make that problem worse.

The warm water might be a nice temperature for bugs to grow; but it's only there for a short time.