This reminds me of my last posting during conscription, the shower handles had a bunch of notches, but in practice it was either icy cold or scorching hot, with only short transitional moment between two modes, so you spent most of showering fidgeting with the handle, starting with icy cold (it was less unbearable) and then switching. But one shower stall was wired wrong, so when you turned cold handle you got hit with scorching hot water instead, quite a surprise and there were even injuries, when I was there one guy sprained his ankle when he jumped out of the stall due to the hot surprise.