I'd appreciate some advice on dealing with this situation both practically and diplomatically.
I've recently moved home to my Mum's house as I couldn't afford to stay in London. I'm living as a lodger, paying rent, my share of bills etc, she doesn't cook/clean etc for me, so very much on lodger status (which I want).
My problem is that it is bitterly cold here. When she puts the heating on (generally just for a few hours morning and evening) she will not turn the thermostat above 16 degrees. She says she cannot afford anymore, but a) this is not true and b) I have offered to pay a higher proportion of the heating bill. Part of the problem is that she is stuck in the 1950s (I don't mean that in a too cruel a way, but she keeps going on about the good old days before central heating) and also she is very severely obese and I'm sure this keeps her warmer.
There are mould spores and mushroomy type things growing in the house which I'm sure in part is due to the temperature. This worries me a lot as I am allergic to moulds.
I have only been back from holiday a few days, but I can already feel my chest starting to grump, and I can really feel the effect of the cold, particularly overnight. My Mum doesn't understand asthma at all. There's little point trying to teach her as she doesn't 'believe in medicine'. I left home at 18, so she hasn't seen me with severe asthma.
How do I convince her to turn the heating on/up without a massive argument? I'm willing to pay more, so that approach doesn't work. I can feel my asthma going downhill and I'll be at the docs/hosp before long if I don't find a solution.