Does water temperature make a difference when you wash your hands?
A US study has discovered that washing your hands with cold water is as effective as washing them with warm water.
Scientists from Rutgers University coated the hands of 20 participants in a harmless strain of bacteria and then had them wash their hands with varying temperatures of water.
The participants either washed their hands at 15°C, 26 °C or 38 °C with a 0.5ml, 1ml or 2ml of antimicrobial soap.
The temperature of the water was found to make no difference to how the bacteria was washed off.
“People need to feel comfortable when they are washing their hands but as far as effectiveness, this study shows us that the temperature of the water used didn’t matter,” said Professor Donald Schaffner, a Rutgers specialist in food science.
The study, published in the Journal of Food Protection, also discovered how long the average person should wash their hands to remove bacteria.
“We learned even washing for 10 seconds significantly removed bacteria from the hands,” said Schaffner
However, those who work in industries such as restaurants or hospitals, should wash their hands for a greater length of time.
US health guidelines advise hands to be washed with water that is warmer than 38°C though there is not much scientific proof that backs this up.
The Rutgers team believe their findings could help the environment.
“We are wasting energy to heat water to a level that is not necessary,” Schaffner said.
The researchers hope more work will be done to establish the prime conditions for washing hands such as looking at the time you spend lathering them in soap and how you dry them.
Do you wash your hands with warm or cold water? Let us know in the comments below.