@primek Upon reflection I have had it all the way through as well, though yesterday was the worst. I don't know why I wasn't joining the dots. The heat has definitely played a part but not yesterday. The women in my family have low blood pressure and my mother told me yesterday that my grandmother used to keel over regularly with this problem! Which I never knew. If I was having more chemotherapy I'd be alert to it moving forward but thank goodness I'm not.
My heart rate tends to be low as well (when I was in labour with my son a midwife asked me if I was an athlete... I am SO not!) but the other night I noticed it was unusually and uncomfortably so. I measured it on my phone app and it was 46bpm. I think I might mention it to my GP next time I see her.