As popularity increases with the installation of under floor heating, we felt it would be useful to talk about solid wood floors alongside under floor heating. We would not recommend  solid wood flooring  in a room where there are fluctuations in moisture and temperature ,such as bathrooms and kitchens, this is because when temperatures and moisture levels increase , solid wood expands, and when the temperature and moisture levels drop the wood contacts, when expansion and contraction of the wood is frequent, it can start to cup and bow and gaps can appear in your floor, spoiling the look of the floor

With underfloor heating the temperature is regularly changing so your solid wood flooring is regularly expanding and contracting and the fact that wood is a natural insulator you could start to get problems, a better option would be to choose an engineered wood floor, which is constructed in a way as to restrict significant expansion and contraction in  extreme conditions, so is a better choice for installation over under floor heating.