UK. Cold and hot water coming from separate taps. WTF? I was once told that it is because hot water boilers used to have their tops open to the outside, which meant the hot water could contain some debris, so it was important to use it only for washing and not let it mix with cooking water. But in bathrooms in some modern builds that definitely don't use that kind of boilers you still get separate taps. I told one of my British colleagues about how it's been bothering me since I moved here and she said "oh yeah, I never realised that I've never seen that in any other country". She also told me that kids are just taught to wash their hands quickly under the hot tap, so that they don't run the water long enough for it to turn scolding hot. WTactualF?