Even in deserts, cotton has some of the same drawbacks. It can get very cold at night, due to the extreme temperature variations of dry air. Coolmax is much superior in my experience, even for hot days. I use cotton in bandannas (for keeping glasses clean), in a full rim boonie style hat (useful for saturating with water during the day - its long drying time is a plus in this application) and oh, yes, for dressings and bandages.