Hot water increases bloodflow to the skin, it can definately stir things up a bit.
Have you tried switching shampoo/conditioner?
Borax and apple cider vinegar rinse is known to be very helpful for the scalp, and very anti-fungal, it might be worth a try. It's something you make at home and apply to the hair instead of shampoo (rub it in and all), and then just rinse out again without applying conditioner. If you prefer baths, there's no problems with having the rinse in your bathwater afterwards (in fact it's considered quite beneficial for the skin). :-)
Diet is always a key issue to look at, you might have some issues to address there.