As far as scalp-grinding goes, it is (a) likely to be a protective mechanism which will reduce rotational injury, and (b) can be easily ameliorated, to some degree, by baseball cap, cycling cap, or do-rag. No need for bulky, hot, styrofoam.

My favorite hot-weather headgear is a do-rag. Dip it in a stream, slap it on, air-conditioned brain cells for the next hour.