My mother has mixed dementia - Vascular came 1st(but was generally undiagnosed). Then came Alzheimer's. Before my mum went into a care home she used to keep saying she felt like her body was falling to one side, same side always. She also began to have a lot of falls. Last August(I think it was) this sort of unbalanced feeling got worse and was particularly bad when the weather got warmer(as it is now). I now believe that although that wasn't necessarily causing what she was feeling it made it worse.was.I kept trying to leave her drinks and instructions and phoning about needing to drink and when but....I suppose, with the dementia, "You can lead a horse to water but you can't make it drink" After one of her falls and a spell in hospital they could find no reason for the unbalanced feeling but the consultant who dealt with her did say that it was often a symptom of dementia, a bit of brain death which affects movement. This was something I hadn't been aware of up until then but found other people who said the same on this site. Your mother's dizziness may be nothing like that but, in this current hot spell, this would be my 1st thought around being able to improve things, if possible. My mother's last fall, last August, late on, was down the stairs and that broken hip ultimately put her in a care home....where surprisingly she seems much more contented.