My siblings and I have never seen eye to eye on things.
In particular, my brother.
He was the worst offender and made life difficult for my parents and I when I was still living at home. He had to have his preferred indoor air temperature preferences. If he didn’t he would raise hell until my parents gave in to his demands. Needless to say, it caused a lot of arguments and it really didn’t help that his preferred temperature preferences were a bit to the extreme. Most normal people will have their air warm or cool depending on the weather outside. My brother does too, but he takes it too far. During the summer, he would have the a/c on blast and it would be so cold in the house that I would have to wrap up in blankets in the middle of the summer. In the winter he would turn the furnace up so much I would be sweating. I called him an insensitive idiot, after he clearly saw the rest of us were miserable but he didn’t care. As long as he could freeze or fry himself. Finally my dad put an end to it, and out his foot down. If my brother was going to cause problems then let him. My dad told him either have normal temperatures like any other sane person, or leave. Because it wasn’t right or healthy for the rest of us to suffer. My brother was 19 and he left. We have got to live a normal life since then and for the first time in a long time, the thermostat has remained untouched and the heating and cooling bills are stable.