Washing your hands with hot or cold water - is there a difference?
Do you wash your hands with cold water or hot? And is there a difference?
It was a lesson that Matron on the hospital ward used to personify (and for the life of me I can't get the image of Hattie Jacques out of my head!) - but even here, in the sterile confines of white washed hospital wards, these lessons were forgotten. And amongst the wider population, hand washing seems to have fallen out of our regular ablutions.
It has taken the likes of MRSA and the threat of antibiotic resistance to put hand washing back on the agenda.
With the WHO in 2011 launching a new initiative with the headline: "When clean care is safer care," it seems that simple hand washing is amongst the foremost tools in our box for infection control amongst the medical community. The food preparation industry has also upped its game: last year, E Coli in prepared salad was responsible for two deaths in the UK and over 100 infections.
In the UK alone last year, 40,000 cases of E Coli were confirmed - with some hospitals reporting this as a near doubling than the previous year. And some of these cases show signs that the bug is becoming resistant to our antibiotics.
So have you started to wash your hands more frequently? And do you use hot water, or cold? And is there a difference?
In a recent study in the USA, it appears that the answer to this question is that there is no difference. Washing with hot water doesn't confer any advantage over washing with cold. But let's look at the methodology of this study, published in the Journal of Food Protection.
21 people were followed over the course of six months. That's a tiny sample. These volunteers had their hands exposed to various bacteria, and washed their hands at various temperatures, using different kinds of soap (some being marketed as 'antibacterial' on the label).
The conclusions were that neither the temperature or the type of soap made any difference to removing the bacteria on your hands after 10 seconds of washing - and such a wash 'did remove a significant number of bacteria from their hands.' Indeed, the study found that washing for 30 seconds was even better in removing the bacteria from the hands - so it appears that the time 'in the water flow' was the most important factor.
Using hot water to wash your hands has become a cultural norm: it makes us feel 'cleaner' after we wash and that mental comfort perhaps encourages us to keep washing our hands - practically, I might add that when you use hot water to wash your hands, you also keep your hands under the flow for a few seconds longer as the water might take time to warm. So whilst hot water itself might not make much difference to the bacteria removed, using it might keep our filthy mitts under the tap for those vital few seconds longer.
But the soap, it appears, is optional - although as with hot water, using it might encourage us to keep our hands in the stream for a few more seconds too! (Although some soaps might be more harmful than previously thought - but there is another article on that to come).
So, what are your thoughts? Are you a Hot Wash, or a Cold Wash person?