I have several PV kilts, some of which have very much a woolen look and feel (a couple of them actually do contain a little wool), and others which closely resemble a slightly heavy, tightly woven cotton or cotton-polyester twill. The latter are the ones I favor for really hot weather, of which we usually get a lot here in the US Midwest. They are very comfortable for that--definitely more so than pants and arguably more so than shorts--due to the extra "ventilation" provided by a kilt's open, unbifurcated design. And as Theridion notes, their easy-care quality make them a practical choice as well.