Basic-Wedge, you couldn't be more wrong.
The best hot weather balaclava:
Outdoor Research FR Ninja Balaclava HE
http://military.outdoorresearch.com/...aclava_he.html
The Cool Knit fabric is a very lightweight and can be worn a variety of ways. It's lighter weight than the other nomex balaclav and also the best fitting. Instead of a flat pattern sewn together in the middle, it's shaped to the head with six separate panels sewn together with flat seams. The cut, combined with the stretch nomex makes it conform better to the head and neck than any other design - a 'true' 3-D cut for the head. The bib has ample material for tucking into the collar.