My 2¢ worth,
Either perforated leather, or textile mesh are the two choices, of which I own both. I have found that wearing Under Armour Heat Gear garments is a major plus. I have even found myself feeling a little cold sometimes.
Keep in mind the colors of the gear, lighter colors will be cooler, this goes for the helmet as well, I own several helmets, and my go-to one in the summer is a Fulmer M1 in silver, with an IRIDIUM BLACK SHEILD, it vents extremely well.
Strangely enough it's hard to find mesh gear in light colors. As always make sure with no matter what you get, it has CE ARMOUR, especially the back protection, some jackets don't come with it, they use only a piece of foam, which is not CE armour.
Hydration is important, so be sure to stay that way. Watch the color of your urine
