In reply to HammondR:
I would say: If you want it to hand, don't have it in a bag.
I would only use a bag to protect the camera when in storage, i.e. inside my main bag, to stop it getting bashed and crushed by my other stuff.
If you are going to be using your camera, getting in and out of a bag will just add to the hassle and prevent you from getting the shot. I like the Peak design system of attaching a camera to your shoulder / waist strap, as it stops the camera swinging around and keeps it close to your body, where it is safe.
The only problem with that for ski touring / alpinism is the cold which can kill batteries quite quickly. If you are going to keep it inside your bag, get the smallest, least obtrusive pouch you can get, otherwise it starts taking up a lot of valuable pack space. Also think about where you pack it, I fell with my D3200 in the bottom of my pack and it smashed into my hip, breaking the battery compartment door, and hurting quite a bit.