 All right, so there is also an architecture for hot climates. Tropical is more difficult, but for the hot climates that have colder nights, there is this architecture of creating a drought through heating up. So it's sort of a solar cooling system that is without, well, machinery. So there are some structures of the building that will heat up through the sunshine and then they will create air to be rising and this air goes through the building and cools it down. And that's something that can work very nicely in specific climates, but I was involved in a design review for a building in Abu Dhabi and they had created a building where this was planned. This was Masdar City, the eco-town development on a very large scale. And they had made such chimneys with the idea to draw in air and to create airflow without machinery. And the idea was nice, but then I realized when I was in a meeting in Chicago on the building, this was okay, 10 months of the year. But then there are these two months in that region in the Emirates and the Gulf States where the outside temperature is exceeding 50 degrees, humidity 90 percent. So it's actually, it is sauna, it's not like sauna, it is sauna, it's horrible. You cannot be outside for a few minutes, it's absolutely unbearable. And so imagine if you make chimneys that are drawing in temperature of 50 degrees into the building, so it will heat up maximum speed and so for two months of the year it wouldn't make any sense. So don't apply rules just because you heard that and you like the idea, but rethink. Is this applicable in this situation? And I then suggested that there would be curtains that will be put down in these hottest months to keep the hot air out from the beginning for not heating up the building too much.