| Heating is much easier, but in the right conditions you can still do a lot without power. - The simplest is just having thermal mass to average day and night temperature. As long as the night is cold enough you can just stay in a brick or clay building with thick walls, preferably painted white. - If you want to get a bit more advanced, you can use evaporative cooling, like Persian Yakhchāls [1]. - If you go high-tech, certain paints can cool surfaces down by a couple degrees (by radiating heat at frequencies that don't get absorbed by the atmosphere, thus breaking the equilibrium between heat absorption and heat emission). Of course there is a point where those fail. Evaporative cooling is dependent on a low wet-bulb temperature and fails quickly in humid climate. Thermal mass needs temperature differences. Paints only buy you a couple degrees. In contrast an AC can be scaled to much higher temperatures. 1: https://en.wikipedia.org/wiki/Yakhch%C4%81l |