I haven't used a single layer, but I can say that I've never had a problem staying cool in my double layer. Last summer it was a great place to cool off when daytime temps hit 90. At night I still had to use a pad. It certainly doesn't feel like the extra layer is doing anything to keep me warm (which isn't a bad thing).

Quote Originally Posted by 1csleptonkayak View Post
Is it a big difference staying cool in the double layer vs. single layer during hot, humid conditions?