
For anyone unlucky enough to find themselves in a situation with a bike crash victim, here's how to remove the helmet safely... One person (the more experienced, or sensible, if possible) essentially straddle the patient & gently work their hands up either side of the neck & head inside the helmet to support the neck in every way possible. When they are ready, another person can gently & very slowly remove the helmet.
Basically, if they're screwed, you're not going to do any further damage. All the horror stories we hear of riders' heads exploding when helmets are removed can be true to an extent, but basically, keeping the helmet on isn't going to change that.