I've been having hot showers too but my husband hasn't and we have avoided bites for a day or two but then again haven't been at the plot as much. I put wellies of to pick blackberries and didn't get my body near to the bush as I read that mites like it around blackberries. I must have looked stupid in wellies!
If I remember rightly, one of the websites stated that harvest mites don't bite exposed skin - so maybe we are tackling this the wrong way by covering up!!! But I don't fancy trying the 'naked gardening' method around those brambles though.
Sorry to hear about your husband's bite. There have been quite a few newspaper articles recently that say that this type of problem is on the increase.