Nights on a Uyuni desert tour can be extremely cold, largely because of the high altitude, dry air, and exposed landscape. Temperatures can fall below freezing, even during periods when daytime conditions are relatively mild. Heating in remote accommodations is often limited, making proper clothing especially important after sunset. Pack several warm layers, including thermal base layers, a well-insulated jacket, warm socks, and other cold-weather essentials to stay comfortable during overnight stays.