That's really reassuring, guys. Also a bonus to have two recommendations for the same flooring.
I laid an oak floor in the upstairs landing of our house and in one area the oak board lies almost on top of two central heating pipes (unlagged...there just wasn't the space....centuries old oak beams aren't always where you want them

). This board has shrunk much more noticeably compared to the others (which is what I'd expect) but I just have to live with it.
Roger
Edit update: If thick hardwood flooring is a good insulator (but assuming that the insulation of what the flooring is laid on is better) then where does all the heat go? Surely it's going to come out of the floor eventually?