Helmet for EMS   

What's the best helicopter helmet for EMS use w/NVG?

Did the HEMS thing for 16 years with my Gallet 250. Compact, good noise suppresion and headset/mike, easy to replace pads and "recondition"; the only issue I had was putting the dern thing on my head in the winter. As I said, "compact", fits close to my head, spread the helmet at the buckle/earcups and tuck my ears in- not always easy with my "Alfred E Neuman" jug-handle ears.

The helmet is stiff, doubly so when it's cold but comfortable and relatively quiet considering I didn't have active noise cancellation. 

NVG, battery pack, not a balance issue although the goggles do add a lot of bulk and some weight.

Whichever helmet you choose, I strongly encourage dual visors, one clear and one tinted for glare.

I always wore polarized lenses, but one should check individual aircraft for compatability- some aircraft windshields are installed 'conforming' to the windshield frame, the stressed areas will 'rainbow', transparent but distracting.