I have argued with with my wife for using the dryer regularly, even in summer

, but I can only say so much to a pregnant mum

.
Heaters are another thing. I just say wear more clothes or bring in the blanket from the bedroom. Again, try telling that to someone who's pregnant with a toddler.
Hot water service is electric but it has an off-peak setting. I always set the timer of our dishwasher to run after midnight. I use cold water when washing clothes and I very, very rarely use the dryer.