NH Hotel in Copenhagen, which is positioned as a five-star property, but their "eco-friendly" centralized air conditioning system—controlled by reception rather than in the room—left something to be desired. It seems the green approach limits guests to adjusting the temperature by just a degree or two, which resulted in a uncomfortably warm night for us when the AC wasn't performing well. We mentioned it at reception the next morning, and the staff member seemed dismissive at first, saying no other rooms were available. After I noted that surely some guests would be checking out soon, they were able to find us a cooler room on a lower floor. If I'd wanted a warmer experience, I'd have chosen a sauna instead. Europe's push toward "green" practices is great, but it felt a bit like an excuse for reduced comfort in a five-star hotel.