>>1441194The biggest thing to keep in mind is that its ridged nature, and manner of suspension keeps it from touching your head. The leather suspension liner, when properly worn, creates a gap between the helmet and the wearer's head, which allows for air circulation, and reduces the amount of heat and humidity trapped between the wearer's head and the helmet.
>>1441342Most pith helmets are still made of pith, because the modern cork trade for thick enough sheet cork is outrageous.