I have today emailed British Heart Foundation and asked for their comments. I've never thought of myself as naive, I feel I was just caught off guard and was trying to be helpful, but in hindsight I should have just explained I don't let strangers into my house and left it at that. I think a lot of young people do these jobs, they're just trying to earn a living like everyone else, but the charities they are working for need to ensure they abide by certain guidelines. I was as concerned for her welfare as I was for my own. I don't want to mistrust everyone I come across, although I'm not daft, and I realise that's the sort of world we live in now. I appreciate all your comments, and perhaps my post will help with awareness if others have doorstep callers. 8 pm is not too late for me to have visitors so maybe I need one of these new doorbells so at least I can see who it is!