Editing DnD Desert Raiders Campaign Conditional Temperature Variations (section)

==== Night ====
When most people think of the desert, they conjure up visions of shimmering heat haze, sand, and blazing sun. These features do exist-during the day. At night, the clear, dry air allows the land to give up the day's heat with frightening rapidity. Within a few hours, the killing heat of the day is replaced by the chill of the night. It is quite possible to succumb to cold in the middle of the desert.
The temperature drop might be as much as three or even four temperature bands, and characters without adequate protection against cold run the risk of hypothermia (see Cold Dangers. page 302 of the Dungeon Master’s Guide, or consult the Frostburn accessory).