The lesson from the tragic death of Natasha Richardson is clear: wear a helmet on the ski slopes.
There is as yet no evidence to indicate whether the actor would have survived had she been wearing one. It has also been argued that widespread helmet use in North America has not cut the death rate among skiers and snowboarders, though the numbers are in any case so small as to make that argument unconvincing.
But there seems little doubt that helmets, which are still less prevalent in Europe, reduce the risk of serious head injuries in collisions or the kind of whiplash fall where the back of the skier's head strikes the ground.
Helmets are comfortable, they don't get soaked and cold in snowstorms - and I do not accept that they affect your ability to hear approaching skiers and boarders.
As to the suggestion that they encourage more reckless behaviour, that smacks of another argument advanced this week - that the availability of condoms encourages promiscuity. Neither view should be taken seriously.