Sometimes this is down to "micro" draughts rather than the temperature. Currently, I am sitting in about 19 degrees C inside and that should be plenty warm but

Sometimes this is down to "micro" draughts rather than the temperature. Currently, I am sitting in about 19 degrees C inside and that should be plenty warm but in my T-shirt, I can feel very low level cold draughts caused by windows, small gaps etc. and some people are definitely more sensitive to these. As others have said though, you can hopefully find a suitable temperature that both of you accept and it won't cost as much to keep it there.