Strima, very good advice there re Power of Attorney. Has to be got before dementia takes over, obviously. I don't know the situation in England but here in Scotland you have a choice of a general one or a continuing and welfare one...the latter is the most useful and most requested.
In another life, yes I have seen old folks with problems being ripped off big time, and indeed once fooled they become targets for every "tradesman" under the sun...ie £6,000 to de-moss a 2 bed semi roof etc. That lady's son went looking for the bloke and spotted him on a roof in the next estate...shouted up that he was calling the police, roof guy told him to do something involving procreation and travel...the son promptly removed the ladder...