A US study says there is no benefit in terms of hygiene from washing in hot water rather than cold. | BBC Health
A small study of 20 people found using water at 15C (59F) left hands as clean as water heated to 38C (100F) . The report is published in the Journal of Food Protection,
In the UK, NHS experts say people can use cold or hot water to wash their hands. They say hands should be washed for at least 20 seconds and stress the importance of using enough soap to cover the whole surface of the hands.
Their guidance focuses on rubbing hands together in various ways to make sure each surface of each hand is clean.
Jensen DA, Macinga DR, Shumaker DJ, et al. Quantifying the Effects of Water Temperature, Soap Volume, Lather Time, and Antimicrobial Soap as Variables in the Removal of Escherichia coli ATCC 11229 from Hands. Journal of Food Protection. Published online May 15 2017