After Micheal  Schumacher accident, (get well soon) there has been much online re helmets and skiing. Here is my 2ps worth copied from something I posted on Facebook. 

Surely to wear or nor wear a helmet is a personal thing, a choice you make after due consideration. To equate it with wearing a seat belt, motorcycle helmet or any other legal requirement is not applicable here and I hope that it is never made so, tricky to enforce if nothing else. I don't wear one, yet. Never say never but I have yet to feel the need. I absolutely understand the arguments and after due consideration choose not to. However if I was teaching on a busy novice area where I could not keep a good lookout for incoming idiots then it might be a different story. I am fortunate to spend much of my teaching time off piste and as such avoid most of the collision hungry yahoos. I know that I could fall, hit my head and perhaps regret the lack of protection but I have been doing this a long long time, am in control ( mostly!) and if I get to an area where the risk is increased I ski appropriately. When I am off piste I carry all the gear, and while in the event of an avalanche I can for located thanks to the transceiver and the ABS bag, I can also find someone who is buried. The point is that equating helmet wearing with transceiver etc use is not valid. A helmet is for your protection, off piste kit is more than that. So, use or don't use a helmet, that's your choice, just respect mine and have fun.