If he has a hot water heater, which I'm assuming he does since he takes hot showers, then it takes very little electricity. The heater is running all the time anyways, so why not get use out of it?
I'd wager a guess and say it was definitely something else that was affecting your electricity bill.
Also, taking hot showers may dry out your skin, but only temporarily. In your epidermis, there are tiny little glands located near your hair follicles (in your skin and on your head) called sebaceous glands that produce oils and sweat naturally. In layman's terms, skin make oil.
So there really shouldn't be any long-term effects to taking multiple hot showers a day. But you never know, anything can give you cancer nowadays. >_>








