Great! My body doesn't adjust to that. It's only a minor hindrance in the grand scheme of things, but it sometimes does annoy me (and others whose comfort zone starts at a slightly higher temperature than the majority) when people think the problem is purely one of lack of acclimatization or grit.

I can adjust to higher temperatures just fine, but not sitting still (even with regular active breaks) at anything below 21°C. Our company used to rent office space when we were a startup in a place that didn't turn on the heating until temperatures outside dropped below a certain threshold. Sometimes this meant 19°C or 20°C for weeks: I don't get used to it; it just stops me being productive (and nice).