Originally Posted by cydewaze
My head is in fact the exact same size as a helmet, so I'll give one of those a try
Here's the another suggestion for people with big head. I have seen NFL players wearing it quite often. If it fits for those super sized humans, it'll fit just about anybody.
Underarmour KP cap
Only problem this has is that it uses mesh top, so it may not prevent your head from getting a tan. I have never tried this nor seen it in real life. Underarnour offers one or two different kind helmet liners for the hot weather, but I haven't seen any NFL players wearing them yet.